diff --git a/.env.test b/.env.test
deleted file mode 100644
index e22b43f..0000000
--- a/.env.test
+++ /dev/null
@@ -1,19 +0,0 @@
-# Test Database Configuration
-DB_HOST=localhost
-DB_PORT=5433
-DB_USERNAME=testuser
-DB_PASSWORD=testpass
-DB_NAME=music_server_test
-
-# Test Paths
-MUSIC_PATH=/Users/sebastian/projects/MusicServer/testMusic
-CHARACTERS_PATH=/Users/sebastian/projects/MusicServer/testCharacters
-
-# Server Configuration
-PORT=8081
-LOG_LEVEL=debug
-LOG_JSON=false
-
-# Session Authentication (for testing)
-# Set to disable session auth during development
-DISABLE_SESSION_AUTH=true
diff --git a/cmd/web/search_test.go b/cmd/web/search_test.go
new file mode 100644
index 0000000..0a3c428
--- /dev/null
+++ b/cmd/web/search_test.go
@@ -0,0 +1,100 @@
+package web
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+
+	"music-server/internal/backend"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var soundtracks = []string{
+	"Call of Duty: Modern Warfare",
+	"Final Fantasy VII",
+	"Joe & Mac",
+	"Kingdom Hearts",
+	"Lemmings (SNES + Mega Drive)",
+	"MG",
+	"Metal Gear Solid 4 - Guns of the Patriots",
+	"Pokémon HeartGold & SoulSilver",
+	"Resident Evil 2 (Remake)",
+	"Ys III - Wanderers from Ys (+The Oath in Felghana)",
+}
+
+func newCache(names []string) *backend.SearchCache {
+	return backend.NewSearchCache(func(context.Context) ([]string, error) { return names, nil })
+}
+
+func searchData(t *testing.T) []backend.SoundtrackData {
+	data, err := newCache(soundtracks).Get(context.Background())
+	require.NoError(t, err)
+	return data
+}
+
+func TestSearch(t *testing.T) {
+	data := searchData(t)
+	tests := []struct {
+		query string
+		want  []string
+	}{
+		// Exact (case-insensitive) substring
+		{"resident", []string{"Resident Evil 2 (Remake)"}},
+		// Ignoring spaces and special characters
+		{"joeandmac", []string{"Joe & Mac"}},
+		{"snes+mega", []string{"Lemmings (SNES + Mega Drive)"}},
+		{"pokemon", []string{"Pokémon HeartGold & SoulSilver"}},
+		// Letters in order
+		{"codmw", []string{"Call of Duty: Modern Warfare"}},
+		{"mgs4gotp", []string{"Metal Gear Solid 4 - Guns of the Patriots"}},
+		{"re2r", []string{"Resident Evil 2 (Remake)"}},
+		// No match
+		{"zzz", nil},
+		// Regex special characters are plain text
+		{"(remake)", []string{"Resident Evil 2 (Remake)"}},
+		{"[", nil},
+	}
+	for _, tt := range tests {
+		t.Run(tt.query, func(t *testing.T) {
+			assert.Equal(t, tt.want, search(tt.query, data))
+		})
+	}
+}
+
+func TestSearchEmptyReturnsEverything(t *testing.T) {
+	assert.Equal(t, soundtracks, search("", searchData(t)))
+}
+
+func TestSearchOrdering(t *testing.T) {
+	// "MG" is an exact match, "Metal Gear Solid..." only matches by letters in order.
+	results := search("mg", searchData(t))
+	require.GreaterOrEqual(t, len(results), 2)
+	assert.Equal(t, "MG", results[0])
+	assert.Contains(t, results, "Metal Gear Solid 4 - Guns of the Patriots")
+}
+
+func TestSearchHandler(t *testing.T) {
+	handler := NewSearchHandler(newCache(soundtracks))
+	req := httptest.NewRequest(http.MethodPost, "/find", strings.NewReader(url.Values{"search_term": {"kingdom"}}.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	rec := httptest.NewRecorder()
+
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Contains(t, rec.Body.String(), "Kingdom Hearts")
+	assert.NotContains(t, rec.Body.String(), "Final Fantasy")
+}
+
+func TestSearchHandlerLoadError(t *testing.T) {
+	cache := backend.NewSearchCache(func(context.Context) ([]string, error) { return nil, errors.New("db down") })
+	rec := httptest.NewRecorder()
+	NewSearchHandler(cache).ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/find", nil))
+	assert.Equal(t, http.StatusInternalServerError, rec.Code)
+}
diff --git a/compose.test.yaml b/compose.test.yaml
deleted file mode 100644
index 07d8e35..0000000
--- a/compose.test.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-version: '3.8'
-
-services:
-  test-db:
-    image: postgres:15-alpine
-    environment:
-      POSTGRES_USER: testuser
-      POSTGRES_PASSWORD: testpass
-      POSTGRES_DB: music_server_test
-    ports:
-      - "5433:5432"
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U postgres -d postgres"]
-      interval: 5s
-      timeout: 5s
-      retries: 5
-    volumes:
-      - test-db-data:/var/lib/postgresql/data
-
-volumes:
-  test-db-data:
diff --git a/internal/backend/characters_test.go b/internal/backend/characters_test.go
new file mode 100644
index 0000000..e25a076
--- /dev/null
+++ b/internal/backend/characters_test.go
@@ -0,0 +1,58 @@
+package backend
+
+import (
+	"io"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func newCharacterService(t *testing.T) *CharacterService {
+	t.Helper()
+	base := t.TempDir()
+	writeFile(t, filepath.Join(base, "secret.png"), "outside")
+	dir := filepath.Join(base, "characters")
+	writeFile(t, filepath.Join(dir, "Adol.png"), "adol")
+	writeFile(t, filepath.Join(dir, "Aloy.JPG"), "aloy")
+	writeFile(t, filepath.Join(dir, "notes.txt"), "text")
+	writeFile(t, filepath.Join(dir, "sub", "Hidden.png"), "hidden")
+
+	c, err := NewCharacterService(dir)
+	require.NoError(t, err)
+	t.Cleanup(func() { c.Close() })
+	return c
+}
+
+func TestCharacterList(t *testing.T) {
+	characters, err := newCharacterService(t).List()
+	require.NoError(t, err)
+	assert.Equal(t, []string{"Adol.png", "Aloy.JPG"}, characters)
+}
+
+func TestCharacterOpen(t *testing.T) {
+	c := newCharacterService(t)
+
+	f, err := c.Open("Adol.png")
+	require.NoError(t, err)
+	content, _ := io.ReadAll(f)
+	f.Close()
+	assert.Equal(t, "adol", string(content))
+
+	_, err = c.Open("Missing.png")
+	assert.ErrorIs(t, err, ErrNotFound)
+}
+
+func TestCharacterOpenRejectsPathTraversal(t *testing.T) {
+	c := newCharacterService(t)
+	for _, name := range []string{"", "../secret.png", "sub/Hidden.png", "/etc/passwd", "..", "notes.txt"} {
+		_, err := c.Open(name)
+		assert.ErrorIs(t, err, ErrInvalidName, name)
+	}
+}
+
+func TestNewCharacterServiceMissingDir(t *testing.T) {
+	_, err := NewCharacterService(filepath.Join(t.TempDir(), "missing"))
+	assert.Error(t, err)
+}
diff --git a/internal/backend/main_test.go b/internal/backend/main_test.go
new file mode 100644
index 0000000..d4cb727
--- /dev/null
+++ b/internal/backend/main_test.go
@@ -0,0 +1,15 @@
+//go:build !integration
+
+package backend
+
+import (
+	"os"
+	"testing"
+
+	"music-server/internal/logging"
+)
+
+func TestMain(m *testing.M) {
+	logging.Init("fatal", false)
+	os.Exit(m.Run())
+}
diff --git a/internal/backend/music_test.go b/internal/backend/music_test.go
new file mode 100644
index 0000000..1747db5
--- /dev/null
+++ b/internal/backend/music_test.go
@@ -0,0 +1,224 @@
+package backend
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"music-server/internal/db/repository"
+	"music-server/internal/testutil/fakedb"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func writeFile(t *testing.T, path, content string) {
+	t.Helper()
+	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0o755))
+	require.NoError(t, os.WriteFile(path, []byte(content), 0o644))
+}
+
+// addSoundtrackWithSongs creates a soundtrack folder with song files and matching database rows.
+func addSoundtrackWithSongs(t *testing.T, store *fakedb.Store, musicDir, name string, timesPlayed int32, songs ...string) repository.Soundtrack {
+	t.Helper()
+	dir := musicDir + "/" + name + "/"
+	st := store.AddSoundtrack(repository.Soundtrack{SoundtrackName: name, Path: dir, TimesPlayed: timesPlayed})
+	for _, song := range songs {
+		fileName := song + ".mp3"
+		writeFile(t, dir+fileName, song)
+		store.AddTestSong(repository.Song{SoundtrackID: st.ID, SongName: song, Path: dir + fileName, FileName: &fileName})
+	}
+	return st
+}
+
+func TestMusicServiceEmptyQueue(t *testing.T) {
+	m := NewMusicService(fakedb.New(), t.TempDir())
+
+	_, err := m.NextSong()
+	assert.ErrorIs(t, err, ErrQueueEmpty)
+	_, err = m.PreviousSong()
+	assert.ErrorIs(t, err, ErrQueueEmpty)
+	_, err = m.Song(0)
+	assert.ErrorIs(t, err, ErrQueueEmpty)
+	assert.Equal(t, SongInfo{}, m.SongInfo(context.Background()))
+	assert.Empty(t, m.PlayedSongs(context.Background()))
+	assert.NoError(t, m.AddLatestPlayed(context.Background()))
+	assert.NoError(t, m.SetPlayed(context.Background(), -1))
+}
+
+func TestMusicServiceNoSoundtracks(t *testing.T) {
+	m := NewMusicService(fakedb.New(), t.TempDir())
+	ctx := context.Background()
+
+	_, err := m.RandomSong(ctx)
+	assert.ErrorIs(t, err, ErrNoSongs)
+	_, err = m.RandomSongLowChance(ctx)
+	assert.ErrorIs(t, err, ErrNoSongs)
+	_, err = m.RandomSongClassic(ctx)
+	assert.ErrorIs(t, err, ErrNoSongs)
+}
+
+func TestMusicServiceSoundtracksWithoutSongs(t *testing.T) {
+	store := fakedb.New()
+	store.AddSoundtrack(repository.Soundtrack{SoundtrackName: "Empty"})
+	m := NewMusicService(store, t.TempDir())
+
+	_, err := m.RandomSong(context.Background())
+	assert.ErrorIs(t, err, ErrNoSongs)
+}
+
+func TestMusicServiceQueue(t *testing.T) {
+	store := fakedb.New()
+	musicDir := t.TempDir()
+	addSoundtrackWithSongs(t, store, musicDir, "Game A", 0, "Song 1", "Song 2")
+	m := NewMusicService(store, t.TempDir())
+	ctx := context.Background()
+
+	first, err := m.RandomSong(ctx)
+	require.NoError(t, err)
+	m.AddLatestToQueue()
+	second, err := m.RandomSong(ctx)
+	require.NoError(t, err)
+	m.AddLatestToQueue()
+
+	info := m.SongInfo(ctx)
+	assert.Equal(t, "Game A", info.Soundtrack)
+	assert.Equal(t, 1, info.SongNo)
+	assert.True(t, info.CurrentlyPlaying)
+
+	path, err := m.PreviousSong()
+	require.NoError(t, err)
+	assert.Equal(t, first, path)
+	path, err = m.PreviousSong()
+	require.NoError(t, err)
+	assert.Equal(t, first, path, "previous stays on the first song")
+
+	path, err = m.NextSong()
+	require.NoError(t, err)
+	assert.Equal(t, second, path)
+	path, err = m.NextSong()
+	require.NoError(t, err)
+	assert.Equal(t, second, path, "next stays on the last song")
+
+	path, err = m.Song(99)
+	require.NoError(t, err)
+	assert.Equal(t, second, path, "song number is clamped")
+
+	played := m.PlayedSongs(ctx)
+	require.Len(t, played, 2)
+	assert.False(t, played[0].CurrentlyPlaying)
+	assert.True(t, played[1].CurrentlyPlaying)
+
+	require.NoError(t, m.Reset(ctx))
+	_, err = m.NextSong()
+	assert.ErrorIs(t, err, ErrQueueEmpty)
+}
+
+func TestMusicServiceAddLatestToQueueWithoutFetch(t *testing.T) {
+	m := NewMusicService(fakedb.New(), t.TempDir())
+	m.AddLatestToQueue()
+	_, err := m.NextSong()
+	assert.ErrorIs(t, err, ErrQueueEmpty)
+}
+
+func TestMusicServiceMarkPlayed(t *testing.T) {
+	store := fakedb.New()
+	st := addSoundtrackWithSongs(t, store, t.TempDir(), "Game A", 0, "Song 1")
+	m := NewMusicService(store, t.TempDir())
+	ctx := context.Background()
+
+	_, err := m.RandomSong(ctx)
+	require.NoError(t, err)
+	m.AddLatestToQueue()
+
+	require.NoError(t, m.AddLatestPlayed(ctx))
+	require.NoError(t, m.SetPlayed(ctx, 0))
+	require.NoError(t, m.SetPlayed(ctx, 5), "out of range is ignored")
+
+	updated, _ := store.Soundtrack("Game A")
+	assert.Equal(t, int32(2), updated.TimesPlayed)
+	assert.Equal(t, int32(2), store.SongsOf(st.ID)[0].TimesPlayed)
+}
+
+func TestMusicServiceRemovesBrokenSongs(t *testing.T) {
+	store := fakedb.New()
+	musicDir := t.TempDir()
+	st := addSoundtrackWithSongs(t, store, musicDir, "Game A", 0, "Good")
+	missing := "Missing.mp3"
+	store.AddTestSong(repository.Song{SoundtrackID: st.ID, SongName: "Missing", Path: st.Path + missing, FileName: &missing})
+	wav := "Wave.wav"
+	writeFile(t, st.Path+wav, "wav")
+	store.AddTestSong(repository.Song{SoundtrackID: st.ID, SongName: "Wave", Path: st.Path + wav, FileName: &wav})
+	m := NewMusicService(store, t.TempDir())
+
+	for range 20 {
+		path, err := m.RandomSong(context.Background())
+		require.NoError(t, err)
+		assert.Equal(t, st.Path+"Good.mp3", path)
+	}
+	songs := store.SongsOf(st.ID)
+	require.Len(t, songs, 1)
+	assert.Equal(t, "Good", songs[0].SongName)
+}
+
+func TestMusicServiceRandomSongClassic(t *testing.T) {
+	store := fakedb.New()
+	st := addSoundtrackWithSongs(t, store, t.TempDir(), "Game A", 0, "Good")
+	missing := "Missing.mp3"
+	store.AddTestSong(repository.Song{SoundtrackID: st.ID, SongName: "Missing", Path: st.Path + missing, FileName: &missing})
+	m := NewMusicService(store, t.TempDir())
+
+	for range 20 {
+		path, err := m.RandomSongClassic(context.Background())
+		require.NoError(t, err)
+		assert.Equal(t, st.Path+"Good.mp3", path)
+	}
+	assert.Len(t, store.SongsOf(st.ID), 1)
+}
+
+func TestLowChanceWeights(t *testing.T) {
+	soundtracks := []repository.Soundtrack{
+		{SoundtrackName: "Often", TimesPlayed: 30},
+		{SoundtrackName: "Average", TimesPlayed: 20},
+		{SoundtrackName: "Rarely", TimesPlayed: 10},
+	}
+	weights := lowChanceWeights(soundtracks)
+	assert.Equal(t, []int{1, 1, 10}, []int{weights[0].weight, weights[1].weight, weights[2].weight})
+}
+
+func TestAveragePlayed(t *testing.T) {
+	assert.Equal(t, int32(0), averagePlayed(nil))
+	assert.Equal(t, int32(20), averagePlayed([]repository.Soundtrack{{TimesPlayed: 10}, {TimesPlayed: 30}}))
+}
+
+func TestSoundtrackNames(t *testing.T) {
+	store := fakedb.New()
+	store.AddSoundtrack(repository.Soundtrack{SoundtrackName: "B"})
+	store.AddSoundtrack(repository.Soundtrack{SoundtrackName: "A"})
+	m := NewMusicService(store, t.TempDir())
+
+	names, err := m.SoundtrackNames(context.Background())
+	require.NoError(t, err)
+	assert.Equal(t, []string{"A", "B"}, names)
+
+	random, err := m.SoundtrackNamesRandom(context.Background())
+	require.NoError(t, err)
+	assert.ElementsMatch(t, []string{"A", "B"}, random)
+	assert.Equal(t, []string{"A", "B"}, names, "shuffling must not change the cached order")
+}
+
+func TestSoundCheckSong(t *testing.T) {
+	dir := t.TempDir()
+	m := NewMusicService(fakedb.New(), dir)
+	_, err := m.SoundCheckSong()
+	assert.ErrorIs(t, err, ErrNoSongs)
+
+	writeFile(t, filepath.Join(dir, "check.mp3"), "x")
+	path, err := m.SoundCheckSong()
+	require.NoError(t, err)
+	assert.Equal(t, filepath.Join(dir, "check.mp3"), path)
+
+	_, err = NewMusicService(fakedb.New(), filepath.Join(dir, "missing")).SoundCheckSong()
+	assert.Error(t, err)
+}
diff --git a/internal/backend/releases_test.go b/internal/backend/releases_test.go
new file mode 100644
index 0000000..50a7c11
--- /dev/null
+++ b/internal/backend/releases_test.go
@@ -0,0 +1,81 @@
+package backend
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func newGitea(t *testing.T, status int) (*httptest.Server, *atomic.Int32) {
+	var calls atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		calls.Add(1)
+		w.WriteHeader(status)
+		json.NewEncoder(w).Encode(giteaRelease{
+			Id:   1,
+			Name: "v1.2.3",
+			Assets: []giteaAsset{
+				{Name: "MusicPlayer.exe", DownloadUrl: "https://example.com/MusicPlayer.exe"},
+				{Name: "MusicPlayer.x86_64", DownloadUrl: "https://example.com/MusicPlayer.x86_64"},
+			},
+		})
+	}))
+	t.Cleanup(server.Close)
+	return server, &calls
+}
+
+func TestReleaseService(t *testing.T) {
+	server, _ := newGitea(t, http.StatusOK)
+	r := NewReleaseService(server.URL)
+	ctx := context.Background()
+
+	version, err := r.LatestVersion(ctx)
+	require.NoError(t, err)
+	assert.Equal(t, "v1.2.3", version)
+
+	names, err := r.AssetNames(ctx)
+	require.NoError(t, err)
+	assert.Equal(t, []string{"MusicPlayer.exe", "MusicPlayer.x86_64"}, names)
+
+	url, err := r.AssetURL(ctx, ".exe")
+	require.NoError(t, err)
+	assert.Equal(t, "https://example.com/MusicPlayer.exe", url)
+
+	_, err = r.AssetURL(ctx, ".dmg")
+	assert.ErrorIs(t, err, ErrNotFound)
+}
+
+func TestReleaseServiceCachesRelease(t *testing.T) {
+	server, calls := newGitea(t, http.StatusOK)
+	r := NewReleaseService(server.URL)
+	now := time.Now()
+	r.now = func() time.Time { return now }
+	ctx := context.Background()
+
+	for range 3 {
+		_, err := r.LatestVersion(ctx)
+		require.NoError(t, err)
+	}
+	assert.Equal(t, int32(1), calls.Load())
+
+	now = now.Add(releaseCacheTTL + time.Second)
+	_, err := r.LatestVersion(ctx)
+	require.NoError(t, err)
+	assert.Equal(t, int32(2), calls.Load())
+}
+
+func TestReleaseServiceUpstreamErrors(t *testing.T) {
+	server, _ := newGitea(t, http.StatusInternalServerError)
+	_, err := NewReleaseService(server.URL).LatestVersion(context.Background())
+	assert.ErrorIs(t, err, ErrUpstream)
+
+	_, err = NewReleaseService("http://127.0.0.1:1").AssetNames(context.Background())
+	assert.ErrorIs(t, err, ErrUpstream)
+}
diff --git a/internal/backend/search_cache_test.go b/internal/backend/search_cache_test.go
new file mode 100644
index 0000000..bd2c9af
--- /dev/null
+++ b/internal/backend/search_cache_test.go
@@ -0,0 +1,67 @@
+package backend
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCleanSearchTerm(t *testing.T) {
+	tests := map[string]string{
+		"MGS4":          "mgs4",
+		"  test  ":      "test",
+		"Test 123":      "test123",
+		"A+B":           "aplusb",
+		"Mario & Luigi": "marioandluigi",
+		"É":             "e",
+		"It's":          "it's",
+		"Rock 'n Roll":  "rockandroll",
+		"":              "",
+	}
+	for input, expected := range tests {
+		assert.Equal(t, expected, CleanSearchTerm(input), input)
+	}
+}
+
+func TestMatchesSubsequence(t *testing.T) {
+	assert.True(t, MatchesSubsequence("", "anything"))
+	assert.True(t, MatchesSubsequence("ff7", "finalfantasy7"))
+	assert.True(t, MatchesSubsequence("lumière", "clairobscur-lumière"))
+	assert.False(t, MatchesSubsequence("7ff", "finalfantasy7"))
+	// Characters that are special in regular expressions are matched literally.
+	for _, term := range []string{"(", "[", "*", "\\", "a(b", ".*"} {
+		assert.NotPanics(t, func() { MatchesSubsequence(term, "plain text") }, term)
+		assert.False(t, MatchesSubsequence(term, "plain text"), term)
+	}
+	assert.True(t, MatchesSubsequence("(", "game (remake)"))
+}
+
+func TestSearchCache(t *testing.T) {
+	names := []string{"Final Fantasy VII"}
+	calls := 0
+	cache := NewSearchCache(func(context.Context) ([]string, error) {
+		calls++
+		return names, nil
+	})
+	ctx := context.Background()
+
+	data, err := cache.Get(ctx)
+	require.NoError(t, err)
+	assert.Equal(t, []SoundtrackData{{Original: "Final Fantasy VII", Lowercase: "final fantasy vii", Cleaned: "finalfantasyvii"}}, data)
+	_, _ = cache.Get(ctx)
+	assert.Equal(t, 1, calls, "data is cached")
+
+	names = []string{"Chrono Trigger"}
+	require.NoError(t, cache.Reload(ctx))
+	data, _ = cache.Get(ctx)
+	assert.Equal(t, "Chrono Trigger", data[0].Original)
+}
+
+func TestSearchCacheLoadError(t *testing.T) {
+	cache := NewSearchCache(func(context.Context) ([]string, error) { return nil, errors.New("db down") })
+	_, err := cache.Get(context.Background())
+	assert.Error(t, err)
+}
diff --git a/internal/backend/sync_integration_test.go b/internal/backend/sync_integration_test.go
new file mode 100644
index 0000000..2c00d19
--- /dev/null
+++ b/internal/backend/sync_integration_test.go
@@ -0,0 +1,111 @@
+//go:build integration
+
+package backend
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"music-server/internal/db/repository"
+	"music-server/internal/logging"
+	"music-server/internal/testutil/pgtest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMain(m *testing.M) {
+	logging.Init("fatal", false)
+	os.Exit(pgtest.Main(m))
+}
+
+// copyTestMusic copies the repository's testMusic folder so tests can change it.
+func copyTestMusic(t *testing.T) string {
+	t.Helper()
+	dst := t.TempDir()
+	require.NoError(t, os.CopyFS(dst, os.DirFS(filepath.Join("..", "..", "testMusic"))))
+	return dst
+}
+
+// TestSyncWithPostgres runs syncs against a real database to check the SQL queries.
+func TestSyncWithPostgres(t *testing.T) {
+	ctx := context.Background()
+	q := repository.New(pgtest.NewMigratedDatabase(t).Pool)
+	musicDir := copyTestMusic(t)
+	s := NewSyncService(q, musicDir, nil)
+	run := func(full bool) SyncResponse {
+		require.True(t, s.Start(full))
+		s.Wait()
+		result := s.Result()
+		require.Empty(t, result.CatchedErrors)
+		return result
+	}
+
+	result := run(false)
+	assert.Equal(t, []string{"A Bird Story", "Clair Obscur - Expedition 33", "Metal Gear Rising - Revengeance"}, result.SoundtracksAdded)
+
+	soundtracks, err := q.FindAllSoundtracks(ctx)
+	require.NoError(t, err)
+	require.Len(t, soundtracks, 3)
+	bird := soundtracks[0]
+	assert.NotEmpty(t, bird.Fingerprint)
+	songs, err := q.FindSongsFromSoundtrack(ctx, bird.ID)
+	require.NoError(t, err)
+	assert.Len(t, songs, 6)
+
+	// Play a song, then rename one of its files and, in a later sync, the soundtrack folder.
+	// (Renaming both at once changes the content hash, so the folder would count as new.)
+	require.NoError(t, q.AddSongPlayed(ctx, repository.AddSongPlayedParams{SoundtrackID: bird.ID, SongName: "2. Yesterday"}))
+	birdDir := filepath.Join(musicDir, "A Bird Story")
+	require.NoError(t, os.Rename(filepath.Join(birdDir, "2. Yesterday.mp3"), filepath.Join(birdDir, "02 Yesterday.mp3")))
+
+	result = run(false)
+	assert.Equal(t, []string{"A Bird Story"}, result.SoundtracksChangedContent)
+
+	require.NoError(t, os.Rename(birdDir, filepath.Join(musicDir, "A Bird Story (2014)")))
+	result = run(false)
+	assert.Equal(t, map[string]string{"A Bird Story": "A Bird Story (2014)"}, result.SoundtracksChangedTitle)
+	assert.Empty(t, result.SoundtracksAdded)
+	assert.Empty(t, result.SoundtracksRemoved)
+
+	renamed, err := q.GetSoundtrackById(ctx, bird.ID)
+	require.NoError(t, err)
+	assert.Equal(t, "A Bird Story (2014)", renamed.SoundtrackName)
+	songs, err = q.FindSongsFromSoundtrack(ctx, bird.ID)
+	require.NoError(t, err)
+	require.Len(t, songs, 6)
+	var yesterday repository.Song
+	for _, song := range songs {
+		assert.Contains(t, song.Path, "/A Bird Story (2014)/")
+		if song.SongName == "02 Yesterday" {
+			yesterday = song
+		}
+	}
+	assert.Equal(t, int32(1), yesterday.TimesPlayed, "play count survives renames")
+
+	// Nothing changed: the fingerprint lets the sync skip everything.
+	result = run(false)
+	assert.Empty(t, result.SoundtracksChangedContent)
+	assert.Empty(t, result.SoundtracksChangedTitle)
+
+	// Remove a soundtrack and bring it back.
+	mgr := filepath.Join(musicDir, "Metal Gear Rising - Revengeance")
+	backup := filepath.Join(t.TempDir(), "mgr")
+	require.NoError(t, os.Rename(mgr, backup))
+	result = run(false)
+	assert.Equal(t, []string{"Metal Gear Rising - Revengeance"}, result.SoundtracksRemoved)
+	active, err := q.FindAllSoundtracks(ctx)
+	require.NoError(t, err)
+	assert.Len(t, active, 2)
+
+	require.NoError(t, os.Rename(backup, mgr))
+	result = run(true)
+	assert.Equal(t, []string{"Metal Gear Rising - Revengeance"}, result.SoundtracksReAdded)
+
+	// Classic random picks only songs of active soundtracks.
+	row, err := q.GetRandomActiveSong(ctx)
+	require.NoError(t, err)
+	assert.NotEmpty(t, row.SoundtrackPath)
+}
diff --git a/internal/backend/sync_test.go b/internal/backend/sync_test.go
new file mode 100644
index 0000000..d73608f
--- /dev/null
+++ b/internal/backend/sync_test.go
@@ -0,0 +1,398 @@
+package backend
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"music-server/internal/db/repository"
+	"music-server/internal/testutil/fakedb"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func strPtr(s string) *string { return &s }
+
+func TestReconcileSongs(t *testing.T) {
+	keep := repository.Song{Uuid: uuid.New(), Path: "/m/a.mp3", SongName: "a", FileName: strPtr("a.mp3"), Hash: "ha"}
+	changed := repository.Song{Uuid: uuid.New(), Path: "/m/b.mp3", SongName: "b", FileName: strPtr("b.mp3"), Hash: "old"}
+	renamed := repository.Song{Uuid: uuid.New(), Path: "/m/c.mp3", SongName: "c", FileName: strPtr("c.mp3"), Hash: "hc"}
+	removed := repository.Song{Uuid: uuid.New(), Path: "/m/d.mp3", SongName: "d", FileName: strPtr("d.mp3"), Hash: "hd"}
+
+	files := []songFile{
+		{name: "a", fileName: "a.mp3", path: "/m/a.mp3", hash: "ha"},
+		{name: "b", fileName: "b.mp3", path: "/m/b.mp3", hash: "new"},
+		{name: "c2", fileName: "c2.mp3", path: "/m/c2.mp3", hash: "hc"},
+		{name: "e", fileName: "e.mp3", path: "/m/e.mp3", hash: "he"},
+	}
+
+	ops := reconcileSongs([]repository.Song{keep, changed, renamed, removed}, files)
+
+	assert.Equal(t, []songFile{files[3]}, ops.insert)
+	assert.Equal(t, []uuid.UUID{removed.Uuid}, ops.delete)
+	assert.ElementsMatch(t, []songUpdate{
+		{uuid: changed.Uuid, file: files[1]},
+		{uuid: renamed.Uuid, file: files[2]},
+	}, ops.update)
+}
+
+func TestReconcileSongsDuplicateHashes(t *testing.T) {
+	// Two identical files: each existing song may only be matched once.
+	existing := repository.Song{Uuid: uuid.New(), Path: "/m/a.mp3", SongName: "a", FileName: strPtr("a.mp3"), Hash: "h"}
+	files := []songFile{
+		{name: "a", fileName: "a.mp3", path: "/m/a.mp3", hash: "h"},
+		{name: "copy", fileName: "copy.mp3", path: "/m/copy.mp3", hash: "h"},
+	}
+	ops := reconcileSongs([]repository.Song{existing}, files)
+	assert.Empty(t, ops.update)
+	assert.Empty(t, ops.delete)
+	assert.Equal(t, []songFile{files[1]}, ops.insert)
+}
+
+func TestClassify(t *testing.T) {
+	existing := []repository.Soundtrack{
+		{ID: 1, SoundtrackName: "Game A", Hash: "ha"},
+		{ID: 2, SoundtrackName: "Game B", Hash: "hb"},
+	}
+	tests := []struct {
+		name, hash string
+		status     SoundtrackStatus
+		id         int32
+	}{
+		{"Game A", "ha", NotChanged, 1},
+		{"Game A", "changed", SoundtrackChanged, 1},
+		{"Game B renamed", "hb", TitleChanged, 2},
+		{"Game C", "hc", NewSoundtrack, 0},
+	}
+	for _, tt := range tests {
+		status, match := classify(existing, tt.name, tt.hash)
+		assert.Equal(t, tt.status, status, tt.name)
+		if tt.id == 0 {
+			assert.Nil(t, match)
+		} else {
+			assert.Equal(t, tt.id, match.ID)
+		}
+	}
+}
+
+func TestFingerprint(t *testing.T) {
+	dir := t.TempDir()
+	writeFile(t, filepath.Join(dir, "a.mp3"), "one")
+	writeFile(t, filepath.Join(dir, "sub", "b.mp3"), "two")
+
+	first, err := fingerprint(dir)
+	require.NoError(t, err)
+	again, err := fingerprint(dir)
+	require.NoError(t, err)
+	assert.Equal(t, first, again)
+
+	writeFile(t, filepath.Join(dir, "sub", "b.mp3"), "changed size")
+	changed, err := fingerprint(dir)
+	require.NoError(t, err)
+	assert.NotEqual(t, first, changed, "changes in sub folders are detected")
+
+	// Moving the folder keeps the fingerprint, so renames are detected by name lookup failing.
+	moved := filepath.Join(t.TempDir(), "moved")
+	require.NoError(t, os.Rename(dir, moved))
+	afterMove, err := fingerprint(moved)
+	require.NoError(t, err)
+	assert.Equal(t, changed, afterMove)
+}
+
+func TestIsSong(t *testing.T) {
+	dir := t.TempDir()
+	for _, name := range []string{"a.mp3", "b.MP3", "c.wav", "cover.jpg"} {
+		writeFile(t, filepath.Join(dir, name), "x")
+	}
+	require.NoError(t, os.Mkdir(filepath.Join(dir, "folder.mp3"), 0o755))
+	entries, err := os.ReadDir(dir)
+	require.NoError(t, err)
+
+	var songs []string
+	for _, e := range entries {
+		if isSong(e) {
+			songs = append(songs, e.Name())
+		}
+	}
+	assert.Equal(t, []string{"a.mp3", "b.MP3"}, songs)
+	assert.Equal(t, "b", songName("b.MP3"))
+}
+
+// syncFixture is a music folder with a SyncService backed by an in-memory database.
+type syncFixture struct {
+	t     *testing.T
+	dir   string
+	store *fakedb.Store
+	sync  *SyncService
+}
+
+func newSyncFixture(t *testing.T) *syncFixture {
+	dir := t.TempDir()
+	store := fakedb.New()
+	return &syncFixture{t: t, dir: dir, store: store, sync: NewSyncService(store, dir, nil)}
+}
+
+func (f *syncFixture) write(rel, content string) {
+	writeFile(f.t, filepath.Join(f.dir, rel), content)
+}
+
+func (f *syncFixture) run(full bool) SyncResponse {
+	f.t.Helper()
+	require.True(f.t, f.sync.Start(full))
+	f.sync.Wait()
+	require.False(f.t, f.sync.IsSyncing())
+	return f.sync.Result()
+}
+
+func (f *syncFixture) soundtrack(name string) repository.Soundtrack {
+	f.t.Helper()
+	st, ok := f.store.Soundtrack(name)
+	require.True(f.t, ok, "soundtrack %q not found", name)
+	return st
+}
+
+func TestSyncAddsSoundtracksAndSongs(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01 Title.mp3", "a1")
+	f.write("Game A/02 Battle.MP3", "a2")
+	f.write("Game A/cover.jpg", "img")
+	f.write("Game B/01 Intro.mp3", "b1")
+	f.write("old/ignored.mp3", "x")
+	f.write("loose file.mp3", "x")
+
+	result := f.run(false)
+	assert.Equal(t, []string{"Game A", "Game B"}, result.SoundtracksAdded)
+	assert.Empty(t, result.CatchedErrors)
+
+	a := f.soundtrack("Game A")
+	assert.Equal(t, f.dir+"/Game A/", a.Path)
+	assert.NotEmpty(t, a.Hash)
+	assert.NotEmpty(t, a.Fingerprint)
+	songs := f.store.SongsOf(a.ID)
+	require.Len(t, songs, 2)
+	assert.Equal(t, "01 Title", songs[0].SongName)
+	assert.Equal(t, "02 Battle", songs[1].SongName)
+	assert.Equal(t, a.Uuid, songs[0].SoundtrackUuid)
+	assert.NotEmpty(t, songs[0].Hash)
+
+	_, ok := f.store.Soundtrack("old")
+	assert.False(t, ok, "skipped folders are not synced")
+}
+
+func TestSyncSkipsUnchangedSoundtracksByFingerprint(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.run(false)
+
+	// If the folder were hashed again, the stored hash would be replaced.
+	a := f.soundtrack("Game A")
+	require.NoError(t, f.store.UpdateSoundtrackHash(context.Background(), repository.UpdateSoundtrackHashParams{Hash: "stale", ID: a.ID}))
+
+	result := f.run(false)
+	assert.Empty(t, result.SoundtracksAdded)
+	assert.Empty(t, result.SoundtracksChangedContent)
+	assert.Equal(t, "stale", f.soundtrack("Game A").Hash)
+
+	result = f.run(true)
+	assert.NotEqual(t, "stale", f.soundtrack("Game A").Hash, "a full sync always hashes")
+	assert.Empty(t, result.SoundtracksChangedTitle, "a full sync does not report unchanged titles")
+}
+
+func TestSyncDetectsChangedContent(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.write("Game A/02.mp3", "a2")
+	f.run(false)
+	a := f.soundtrack("Game A")
+	before := f.store.SongsOf(a.ID)
+
+	require.NoError(t, os.Remove(filepath.Join(f.dir, "Game A/02.mp3")))
+	require.NoError(t, os.Rename(filepath.Join(f.dir, "Game A/01.mp3"), filepath.Join(f.dir, "Game A/01 renamed.mp3")))
+	f.write("Game A/03.mp3", "a3")
+
+	result := f.run(false)
+	assert.Equal(t, []string{"Game A"}, result.SoundtracksChangedContent)
+
+	after := f.store.SongsOf(a.ID)
+	require.Len(t, after, 2)
+	assert.Equal(t, "01 renamed", after[0].SongName)
+	assert.Equal(t, before[0].Uuid, after[0].Uuid, "renamed song keeps its identity and play count")
+	assert.Equal(t, "03", after[1].SongName)
+}
+
+func TestSyncDetectsRenamedSoundtrack(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.run(false)
+	a := f.soundtrack("Game A")
+	require.NoError(t, f.store.AddSongPlayed(context.Background(), repository.AddSongPlayedParams{SoundtrackID: a.ID, SongName: "01"}))
+
+	require.NoError(t, os.Rename(filepath.Join(f.dir, "Game A"), filepath.Join(f.dir, "Game A Remastered")))
+	result := f.run(false)
+
+	assert.Equal(t, map[string]string{"Game A": "Game A Remastered"}, result.SoundtracksChangedTitle)
+	assert.Empty(t, result.SoundtracksRemoved)
+	assert.Empty(t, result.SoundtracksAdded)
+
+	renamed := f.soundtrack("Game A Remastered")
+	assert.Equal(t, a.ID, renamed.ID)
+	assert.Equal(t, f.dir+"/Game A Remastered/", renamed.Path)
+	songs := f.store.SongsOf(a.ID)
+	require.Len(t, songs, 1)
+	assert.Equal(t, f.dir+"/Game A Remastered/01.mp3", songs[0].Path)
+	assert.Equal(t, int32(1), songs[0].TimesPlayed)
+}
+
+func TestSyncRemovedAndReAdded(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.write("Game B/01.mp3", "b1")
+	f.run(false)
+
+	backup := filepath.Join(t.TempDir(), "Game B")
+	require.NoError(t, os.Rename(filepath.Join(f.dir, "Game B"), backup))
+	result := f.run(false)
+	assert.Equal(t, []string{"Game B"}, result.SoundtracksRemoved)
+	assert.NotNil(t, f.soundtrack("Game B").Deleted)
+
+	// Polling the result must not change it.
+	assert.Equal(t, result, f.sync.Result())
+	assert.Equal(t, result, f.sync.Result())
+
+	require.NoError(t, os.Rename(backup, filepath.Join(f.dir, "Game B")))
+	result = f.run(false)
+	assert.Equal(t, []string{"Game B"}, result.SoundtracksReAdded)
+	assert.Empty(t, result.SoundtracksRemoved)
+	assert.Nil(t, f.soundtrack("Game B").Deleted)
+
+	// A full sync reports re-added soundtracks too.
+	require.NoError(t, os.Rename(filepath.Join(f.dir, "Game B"), backup))
+	f.run(false)
+	require.NoError(t, os.Rename(backup, filepath.Join(f.dir, "Game B")))
+	result = f.run(true)
+	assert.Equal(t, []string{"Game B"}, result.SoundtracksReAdded)
+	assert.Nil(t, f.soundtrack("Game B").Deleted)
+}
+
+func TestSyncUpdatesMovedMusicPath(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.run(false)
+
+	newDir := filepath.Join(t.TempDir(), "music")
+	require.NoError(t, os.Rename(f.dir, newDir))
+	f.dir = newDir
+	f.sync = NewSyncService(f.store, newDir, nil)
+	f.run(false)
+
+	a := f.soundtrack("Game A")
+	assert.Equal(t, newDir+"/Game A/", a.Path)
+	assert.Equal(t, newDir+"/Game A/01.mp3", f.store.SongsOf(a.ID)[0].Path)
+}
+
+func TestSyncIDFileCleanup(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.write("Game A/.5.id", "")
+	f.write("Game B/01.mp3", "b1")
+	f.write("Game B/.6.id", "")
+
+	// Simulate an upgraded database: hashes are known but no fingerprints yet.
+	for _, name := range []string{"Game A", "Game B"} {
+		hash, err := dirHash(filepath.Join(f.dir, name) + "/")
+		require.NoError(t, err)
+		f.store.AddSoundtrack(repository.Soundtrack{SoundtrackName: name, Path: f.dir + "/" + name + "/", Hash: hash})
+	}
+	f.write("Game B/02.mp3", "b2") // Game B changes, Game A does not
+
+	f.run(false)
+	assert.FileExists(t, filepath.Join(f.dir, "Game A/.5.id"), "unchanged soundtracks keep their .id files")
+	assert.NoFileExists(t, filepath.Join(f.dir, "Game B/.6.id"), "changed soundtracks are cleaned up")
+
+	result := f.run(true)
+	assert.NoFileExists(t, filepath.Join(f.dir, "Game A/.5.id"), "a full sync cleans up everything")
+	assert.Empty(t, result.CatchedErrors)
+
+	// The stored fingerprint matches the folder without .id files, so the next sync skips it.
+	a := f.soundtrack("Game A")
+	fp, err := fingerprint(a.Path)
+	require.NoError(t, err)
+	assert.Equal(t, fp, a.Fingerprint)
+}
+
+func TestSyncFullRemovesBrokenSongs(t *testing.T) {
+	f := newSyncFixture(t)
+	f.write("Game A/01.mp3", "a1")
+	f.run(false)
+	gone := f.store.AddTestSong(repository.Song{SoundtrackID: 999, SongName: "gone", Path: "/does/not/exist.mp3"})
+
+	f.run(false)
+	assert.Len(t, f.store.Songs, 2, "changes-only sync leaves other songs alone")
+
+	f.run(true)
+	for _, song := range f.store.Songs {
+		assert.NotEqual(t, gone.Uuid, song.Uuid)
+	}
+}
+
+func TestSyncUnreadableMusicPath(t *testing.T) {
+	store := fakedb.New()
+	existing := store.AddSoundtrack(repository.Soundtrack{SoundtrackName: "Game A"})
+	s := NewSyncService(store, filepath.Join(t.TempDir(), "missing"), nil)
+
+	require.True(t, s.Start(false))
+	s.Wait()
+	result := s.Result()
+	require.Len(t, result.CatchedErrors, 1)
+	assert.Contains(t, result.CatchedErrors[0], "ReadDir")
+	st, _ := store.Soundtrack(existing.SoundtrackName)
+	assert.Nil(t, st.Deleted, "nothing is marked deleted when the music path cannot be read")
+}
+
+func TestSyncStartOnlyOnce(t *testing.T) {
+	release := make(chan struct{})
+	s := NewSyncService(fakedb.New(), t.TempDir(), func(context.Context) { <-release })
+
+	require.True(t, s.Start(false))
+	assert.True(t, s.IsSyncing())
+	assert.False(t, s.Start(true), "a second sync cannot start while one is running")
+
+	close(release)
+	s.Wait()
+	assert.False(t, s.IsSyncing())
+	assert.True(t, s.Start(false))
+	s.Wait()
+}
+
+func TestSyncProgressBeforeFirstSync(t *testing.T) {
+	s := NewSyncService(fakedb.New(), t.TempDir(), nil)
+	assert.Equal(t, "0", s.Progress().Progress)
+	assert.Equal(t, SyncResponse{}, s.Result())
+}
+
+func TestSyncCallsOnCompleteBeforeFinishing(t *testing.T) {
+	var syncingDuringCallback bool
+	var s *SyncService
+	s = NewSyncService(fakedb.New(), t.TempDir(), func(context.Context) { syncingDuringCallback = s.IsSyncing() })
+	require.True(t, s.Start(false))
+	s.Wait()
+	assert.True(t, syncingDuringCallback, "caches are refreshed before requests are let through again")
+}
+
+func TestResetDB(t *testing.T) {
+	store := fakedb.New()
+	store.AddSoundtrack(repository.Soundtrack{SoundtrackName: "A"})
+	store.AddTestSong(repository.Song{SongName: "a"})
+	s := NewSyncService(store, t.TempDir(), nil)
+	require.NoError(t, s.ResetDB(context.Background()))
+	assert.Empty(t, store.Soundtracks)
+	assert.Empty(t, store.Songs)
+}
+
+func TestFormatDuration(t *testing.T) {
+	assert.Equal(t, "01:02:03", formatDuration(time.Hour+2*time.Minute+3*time.Second))
+}
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
new file mode 100644
index 0000000..4098642
--- /dev/null
+++ b/internal/config/config_test.go
@@ -0,0 +1,64 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func env(values map[string]string) func(string) string {
+	return func(key string) string { return values[key] }
+}
+
+func validEnv() map[string]string {
+	return map[string]string{
+		"DB_HOST":         "localhost",
+		"DB_PORT":         "5432",
+		"DB_USERNAME":     "user",
+		"DB_PASSWORD":     "pass",
+		"DB_NAME":         "music",
+		"MUSIC_PATH":      "/music",
+		"CHARACTERS_PATH": "/characters",
+	}
+}
+
+func TestLoadDefaults(t *testing.T) {
+	cfg, err := load(env(validEnv()))
+	require.NoError(t, err)
+	assert.Equal(t, 8080, cfg.Port)
+	assert.Equal(t, "info", cfg.LogLevel)
+	assert.Equal(t, "songs", cfg.SoundCheckPath)
+	assert.Equal(t, DefaultReleasesURL, cfg.ReleasesURL)
+	assert.Empty(t, cfg.TrustedProxies)
+}
+
+func TestLoadMissingRequired(t *testing.T) {
+	values := validEnv()
+	delete(values, "MUSIC_PATH")
+	delete(values, "DB_HOST")
+	_, err := load(env(values))
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "MUSIC_PATH is required")
+	assert.Contains(t, err.Error(), "DB_HOST is required")
+}
+
+func TestLoadTrustedProxies(t *testing.T) {
+	values := validEnv()
+	values["TRUSTED_PROXIES"] = "10.0.0.0/8, 172.16.0.0/12"
+	cfg, err := load(env(values))
+	require.NoError(t, err)
+	require.Len(t, cfg.TrustedProxies, 2)
+	assert.Equal(t, "10.0.0.0/8", cfg.TrustedProxies[0].String())
+
+	values["TRUSTED_PROXIES"] = "not-a-cidr"
+	_, err = load(env(values))
+	assert.ErrorContains(t, err, "TRUSTED_PROXIES")
+}
+
+func TestLoadInvalidPort(t *testing.T) {
+	values := validEnv()
+	values["PORT"] = "abc"
+	_, err := load(env(values))
+	assert.ErrorContains(t, err, "PORT")
+}
diff --git a/internal/db/main_integration_test.go b/internal/db/main_integration_test.go
new file mode 100644
index 0000000..43d8abf
--- /dev/null
+++ b/internal/db/main_integration_test.go
@@ -0,0 +1,16 @@
+//go:build integration
+
+package db_test
+
+import (
+	"os"
+	"testing"
+
+	"music-server/internal/logging"
+	"music-server/internal/testutil/pgtest"
+)
+
+func TestMain(m *testing.M) {
+	logging.Init("error", false)
+	os.Exit(pgtest.Main(m))
+}
diff --git a/internal/db/migration_integration_test.go b/internal/db/migration_integration_test.go
new file mode 100644
index 0000000..5fdfa25
--- /dev/null
+++ b/internal/db/migration_integration_test.go
@@ -0,0 +1,86 @@
+//go:build integration
+
+package db_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"music-server/internal/db"
+	"music-server/internal/testutil/pgtest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func openDatabase(t *testing.T, dbname string) *db.Database {
+	t.Helper()
+	database, err := db.NewDatabase(context.Background(), pgtest.ConnString(dbname))
+	require.NoError(t, err)
+	t.Cleanup(database.Close)
+	return database
+}
+
+func count(t *testing.T, database *db.Database, query string) int {
+	t.Helper()
+	var n int
+	require.NoError(t, database.Pool.QueryRow(context.Background(), query).Scan(&n))
+	return n
+}
+
+// TestMigrationsKeepData applies the migrations step by step with data in between,
+// like a database that was created by an older version.
+func TestMigrationsKeepData(t *testing.T) {
+	ctx := context.Background()
+	database := openDatabase(t, pgtest.NewDatabase(t))
+	m, closeFn, err := database.NewMigrator()
+	require.NoError(t, err)
+	defer closeFn()
+
+	require.NoError(t, m.Steps(4))
+
+	for i := 1; i <= 5; i++ {
+		_, err := database.Pool.Exec(ctx, `INSERT INTO game (game_name, path, hash, added) VALUES ($1, $2, $3, NOW())`,
+			fmt.Sprintf("Manual Game %d", i), fmt.Sprintf("/music/game%d/", i), fmt.Sprintf("hash-%d", i))
+		require.NoError(t, err)
+	}
+	for i, game := range []int{1, 1, 2, 3, 4, 4, 4, 5, 5} {
+		_, err := database.Pool.Exec(ctx, `INSERT INTO song (game_id, song_name, path, hash) VALUES ($1, $2, $3, $4)`,
+			game, fmt.Sprintf("Song %d", i), fmt.Sprintf("/music/game%d/%d.mp3", game, i), fmt.Sprintf("song-hash-%d", i))
+		require.NoError(t, err)
+	}
+
+	require.NoError(t, m.Up())
+	version, dirty, err := m.Version()
+	require.NoError(t, err)
+	assert.False(t, dirty)
+	assert.Equal(t, uint(6), version)
+
+	assert.Equal(t, 5, count(t, database, "SELECT COUNT(*) FROM soundtrack"))
+	assert.Equal(t, 9, count(t, database, "SELECT COUNT(*) FROM song"))
+	assert.Equal(t, 0, count(t, database, "SELECT COUNT(*) FROM song WHERE uuid IS NULL OR soundtrack_uuid IS NULL"))
+	assert.Equal(t, 5, count(t, database, "SELECT COUNT(*) FROM soundtrack WHERE fingerprint = ''"))
+	_, err = database.Pool.Exec(ctx, "SELECT 1 FROM game")
+	assert.Error(t, err, "game table is renamed")
+}
+
+func TestFingerprintMigrationDown(t *testing.T) {
+	database := openDatabase(t, pgtest.NewDatabase(t))
+	m, closeFn, err := database.NewMigrator()
+	require.NoError(t, err)
+	defer closeFn()
+
+	require.NoError(t, m.Up())
+	require.NoError(t, m.Steps(-1))
+	assert.Equal(t, 0, count(t, database,
+		"SELECT COUNT(*) FROM information_schema.columns WHERE table_name = 'soundtrack' AND column_name = 'fingerprint'"))
+	require.NoError(t, m.Up())
+}
+
+func TestRunMigrationsIsIdempotent(t *testing.T) {
+	database := openDatabase(t, pgtest.NewDatabase(t))
+	require.NoError(t, database.RunMigrations())
+	require.NoError(t, database.RunMigrations())
+	assert.Equal(t, "up", database.Health(context.Background())["status"])
+}
diff --git a/internal/db/sql_dump_integration_test.go b/internal/db/sql_dump_integration_test.go
new file mode 100644
index 0000000..b05bfb6
--- /dev/null
+++ b/internal/db/sql_dump_integration_test.go
@@ -0,0 +1,39 @@
+//go:build integration
+
+package db_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"music-server/internal/testutil/pgtest"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestSQLDumps migrates real database dumps (music_*_dump.sql in the repository root, not committed).
+func TestSQLDumps(t *testing.T) {
+	for _, dump := range []string{"music_ref_dump.sql", "music_test_dump.sql", "music_prod_dump.sql"} {
+		t.Run(dump, func(t *testing.T) {
+			path := filepath.Join("..", "..", dump)
+			if _, err := os.Stat(path); err != nil {
+				t.Skipf("%s not found", dump)
+			}
+
+			pgtest.CreateRole(t, "sansan")
+			dbname := pgtest.NewDatabase(t)
+			pgtest.LoadSQLFile(t, dbname, path)
+			database := openDatabase(t, dbname)
+			soundtracksBefore := count(t, database, "SELECT COUNT(*) FROM game")
+			songsBefore := count(t, database, "SELECT COUNT(*) FROM song")
+
+			require.NoError(t, database.RunMigrations())
+
+			assert.Equal(t, soundtracksBefore, count(t, database, "SELECT COUNT(*) FROM soundtrack"))
+			assert.Equal(t, songsBefore, count(t, database, "SELECT COUNT(*) FROM song"))
+			assert.Equal(t, 0, count(t, database, "SELECT COUNT(*) FROM song WHERE uuid IS NULL"))
+		})
+	}
+}
diff --git a/internal/server/handlers_test.go b/internal/server/handlers_test.go
new file mode 100644
index 0000000..7ddb187
--- /dev/null
+++ b/internal/server/handlers_test.go
@@ -0,0 +1,283 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"music-server/internal/backend"
+	"music-server/internal/config"
+	"music-server/internal/db/repository"
+
+	"github.com/jackc/pgx/v5/pgtype"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMusicRandomAndQueue(t *testing.T) {
+	e := newTestEnv(t)
+	e.addSong("Game A", "Song", "0123456789")
+
+	rec := e.do(http.MethodGet, "/music/rand")
+	require.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "audio/mpeg", rec.Header().Get("Content-Type"))
+	assert.Equal(t, "0123456789", rec.Body.String())
+
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/music/addQue").Code)
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/music/addPlayed").Code)
+
+	var info backend.SongInfo
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/music/info").Body.Bytes(), &info))
+	assert.Equal(t, "Game A", info.Soundtrack)
+	assert.Equal(t, "Song", info.Song)
+
+	for _, path := range []string{"/music/next", "/music/previous", "/music?song=0", "/api/v1/music?song=0"} {
+		assert.Equal(t, http.StatusOK, e.do(http.MethodGet, path).Code, path)
+	}
+	assert.Equal(t, http.StatusOK, e.do(http.MethodPut, "/music/played?song=0").Code)
+	assert.Equal(t, http.StatusBadRequest, e.do(http.MethodPut, "/music/played?song=x").Code)
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/music/reset").Code)
+}
+
+func TestMusicRangeRequest(t *testing.T) {
+	e := newTestEnv(t)
+	e.addSong("Game A", "Song", "0123456789")
+
+	rec := e.do(http.MethodGet, "/music/rand", "Range", "bytes=2-5")
+	assert.Equal(t, http.StatusPartialContent, rec.Code)
+	assert.Equal(t, "bytes 2-5/10", rec.Header().Get("Content-Range"))
+	assert.Equal(t, "2345", rec.Body.String())
+	assert.Equal(t, "audio/mpeg", rec.Header().Get("Content-Type"))
+}
+
+func TestMusicEmptyStates(t *testing.T) {
+	e := newTestEnv(t)
+	for _, path := range []string{"/music/next", "/music/previous", "/music?song=0", "/music/rand", "/music/rand/low", "/music/rand/classic"} {
+		assert.Equal(t, http.StatusNotFound, e.do(http.MethodGet, path).Code, path)
+	}
+	assert.Equal(t, http.StatusBadRequest, e.do(http.MethodGet, "/music?song=abc").Code)
+	assert.Equal(t, http.StatusBadRequest, e.do(http.MethodGet, "/music").Code)
+
+	rec := e.do(http.MethodGet, "/music/list")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "null\n", rec.Body.String())
+}
+
+func TestMusicSoundCheck(t *testing.T) {
+	e := newTestEnv(t)
+	rec := e.do(http.MethodGet, "/music/soundTest")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "sound check", rec.Body.String())
+}
+
+func TestMusicSoundtrackLists(t *testing.T) {
+	e := newTestEnv(t)
+	e.addSong("B Game", "Song", "b")
+	e.addSong("A Game", "Song", "a")
+
+	var ordered []string
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/music/all/order").Body.Bytes(), &ordered))
+	assert.Equal(t, []string{"A Game", "B Game"}, ordered)
+
+	var random []string
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/music/all").Body.Bytes(), &random))
+	assert.ElementsMatch(t, ordered, random)
+}
+
+func TestMusicDatabaseError(t *testing.T) {
+	e := newTestEnv(t)
+	e.store.Err = errors.New("db down")
+	assert.Equal(t, http.StatusInternalServerError, e.do(http.MethodGet, "/music/rand").Code)
+	assert.Equal(t, http.StatusInternalServerError, e.do(http.MethodGet, "/music/all/order").Code)
+}
+
+func TestCharacterEndpoints(t *testing.T) {
+	e := newTestEnv(t)
+
+	var list []string
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/characters").Body.Bytes(), &list))
+	assert.Equal(t, []string{"Adol.png", "Aloy.jpg"}, list)
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/character/list").Body.Bytes(), &list))
+	assert.Equal(t, []string{"Adol.png", "Aloy.jpg"}, list)
+
+	rec := e.do(http.MethodGet, "/character?name=Adol.png")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "image/png", rec.Header().Get("Content-Type"))
+
+	rec = e.do(http.MethodGet, "/api/v1/character?name=Aloy.jpg")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "image/jpeg", rec.Header().Get("Content-Type"))
+
+	assert.Equal(t, http.StatusNotFound, e.do(http.MethodGet, "/character?name=Missing.png").Code)
+}
+
+func TestCharacterPathTraversal(t *testing.T) {
+	e := newTestEnv(t)
+	for _, name := range []string{"../secret.png", "..%2Fsecret.png", "%2Fetc%2Fpasswd", "../../etc/passwd", ""} {
+		rec := e.do(http.MethodGet, "/character?name="+name)
+		assert.Equal(t, http.StatusBadRequest, rec.Code, name)
+		assert.NotContains(t, rec.Body.String(), "secret", name)
+	}
+}
+
+func newGitea(t *testing.T, status int) string {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(status)
+		w.Write([]byte(`{"id":1,"name":"v2.0.0","assets":[{"name":"Player.exe","browser_download_url":"https://example.com/Player.exe"}]}`))
+	}))
+	t.Cleanup(server.Close)
+	return server.URL
+}
+
+func TestDownloadEndpoints(t *testing.T) {
+	url := newGitea(t, http.StatusOK)
+	e := newTestEnv(t, func(c *config.Config) { c.ReleasesURL = url })
+
+	rec := e.do(http.MethodGet, "/download")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.JSONEq(t, `"v2.0.0"`, rec.Body.String())
+
+	rec = e.do(http.MethodGet, "/api/v1/download/list")
+	assert.JSONEq(t, `["Player.exe"]`, rec.Body.String())
+
+	rec = e.do(http.MethodGet, "/download/windows")
+	assert.Equal(t, http.StatusFound, rec.Code)
+	assert.Equal(t, "https://example.com/Player.exe", rec.Header().Get("Location"))
+
+	assert.Equal(t, http.StatusNotFound, e.do(http.MethodGet, "/download/linux").Code)
+}
+
+func TestDownloadUpstreamDown(t *testing.T) {
+	e := newTestEnv(t, func(c *config.Config) { c.ReleasesURL = newGitea(t, http.StatusServiceUnavailable) })
+	for _, path := range []string{"/download", "/download/list", "/download/windows"} {
+		assert.Equal(t, http.StatusBadGateway, e.do(http.MethodGet, path).Code, path)
+	}
+}
+
+func withAuth(password string) func(*config.Config) {
+	return func(c *config.Config) {
+		c.DisableSessionAuth = false
+		c.APIPassword = password
+	}
+}
+
+func (e *testEnv) createToken(password string) string {
+	e.t.Helper()
+	rec := e.doBody(http.MethodPost, "/api/v1/token", `{"password":"`+password+`"}`)
+	require.Equal(e.t, http.StatusOK, rec.Code, rec.Body.String())
+	var resp TokenResponse
+	require.NoError(e.t, json.Unmarshal(rec.Body.Bytes(), &resp))
+	assert.Equal(e.t, "web", resp.ClientType)
+	assert.WithinDuration(e.t, time.Now().Add(tokenLifetime), resp.ExpiresAt, time.Minute)
+	return resp.Token
+}
+
+func TestTokenAuth(t *testing.T) {
+	e := newTestEnv(t, withAuth("secret"))
+
+	assert.Equal(t, http.StatusUnauthorized, e.do(http.MethodGet, "/api/v1/version").Code)
+	assert.Equal(t, http.StatusUnauthorized, e.do(http.MethodGet, "/api/v1/version", "Authorization", "Basic abc").Code)
+	assert.Equal(t, http.StatusUnauthorized, e.do(http.MethodGet, "/api/v1/version", "Authorization", "Bearer unknown").Code)
+	assert.Equal(t, http.StatusUnauthorized, e.doBody(http.MethodPost, "/api/v1/token", `{"password":"wrong"}`).Code)
+	assert.Equal(t, http.StatusBadRequest, e.doBody(http.MethodPost, "/api/v1/token", `{not json`).Code)
+
+	token := e.createToken("secret")
+	auth := []string{"Authorization", "Bearer " + token}
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/api/v1/version", auth...).Code)
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/version").Code, "legacy routes need no token")
+
+	assert.Equal(t, http.StatusOK, e.do(http.MethodDelete, "/api/v1/token", auth...).Code)
+	assert.Equal(t, http.StatusUnauthorized, e.do(http.MethodGet, "/api/v1/version", auth...).Code)
+	assert.Equal(t, http.StatusUnauthorized, e.do(http.MethodDelete, "/api/v1/token").Code)
+}
+
+func TestTokenOpenAccessWithoutPassword(t *testing.T) {
+	e := newTestEnv(t, withAuth(""))
+	token := e.createToken("anything")
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/api/v1/version", "Authorization", "Bearer "+token).Code)
+}
+
+func TestTokenCleanupRequiresAuth(t *testing.T) {
+	e := newTestEnv(t, withAuth("secret"))
+	assert.Equal(t, http.StatusUnauthorized, e.do(http.MethodPost, "/api/v1/token/cleanup").Code)
+
+	token := e.createToken("secret")
+	e.store.Sessions["old"] = repository.Session{Token: "old", ExpiresAt: pgtype.Timestamptz{Time: time.Now().Add(-time.Hour), Valid: true}}
+	assert.Equal(t, http.StatusOK, e.do(http.MethodPost, "/api/v1/token/cleanup", "Authorization", "Bearer "+token).Code)
+	assert.False(t, e.store.HasSession("old"))
+	assert.True(t, e.store.HasSession(token))
+}
+
+func TestExpiredTokenIsDeleted(t *testing.T) {
+	e := newTestEnv(t, withAuth("secret"))
+	_, err := e.store.CreateSession(context.Background(), repository.CreateSessionParams{
+		Token:     "expired",
+		ExpiresAt: pgtype.Timestamptz{Time: time.Now().Add(-time.Minute), Valid: true},
+	})
+	require.NoError(t, err)
+
+	rec := e.do(http.MethodGet, "/api/v1/version", "Authorization", "Bearer expired")
+	assert.Equal(t, http.StatusUnauthorized, rec.Code)
+	assert.Contains(t, rec.Body.String(), "Token expired")
+	// The fake refuses to delete with a cancelled context, like a real database would.
+	assert.Eventually(t, func() bool { return !e.store.HasSession("expired") }, time.Second, 10*time.Millisecond)
+}
+
+func TestTokenRateLimit(t *testing.T) {
+	e := newTestEnv(t)
+	for range 10 {
+		assert.Equal(t, http.StatusOK, e.doBody(http.MethodPost, "/api/v1/token", `{}`).Code)
+	}
+	rec := e.doBody(http.MethodPost, "/api/v1/token", `{}`)
+	assert.Equal(t, http.StatusTooManyRequests, rec.Code)
+	assert.Contains(t, rec.Body.String(), "Rate limit exceeded")
+}
+
+// statsStore returns canned statistics.
+type statsStore struct {
+	repository.Querier
+	err error
+}
+
+func (s statsStore) GetMostPlayedSoundtracksWithSongs(_ context.Context, limit int32) ([]repository.GetMostPlayedSoundtracksWithSongsRow, error) {
+	return []repository.GetMostPlayedSoundtracksWithSongsRow{{
+		SoundtrackID:   int32(limit),
+		SoundtrackName: "Game A",
+		Songs:          []byte(`[{"song_name":"Song","times_played":3}]`),
+	}}, s.err
+}
+
+func (s statsStore) GetStatisticsSummary(context.Context) (repository.GetStatisticsSummaryRow, error) {
+	return repository.GetStatisticsSummaryRow{TotalSoundtracks: 5, AvgSoundtrackPlays: 1.5}, s.err
+}
+
+func TestStatisticsEndpoints(t *testing.T) {
+	e := newTestEnv(t)
+	e.server.stats = backend.NewStatisticsService(statsStore{})
+	e.handler = e.server.RegisterRoutes()
+
+	var soundtracks []backend.SoundtrackWithSongs
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/statistics/soundtracks/most-played").Body.Bytes(), &soundtracks))
+	require.Len(t, soundtracks, 1)
+	assert.Equal(t, int32(10), soundtracks[0].SoundtrackID, "default limit")
+	assert.Equal(t, "Song", soundtracks[0].Songs[0].SongName)
+
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/statistics/soundtracks/most-played?limit=500").Body.Bytes(), &soundtracks))
+	assert.Equal(t, int32(100), soundtracks[0].SoundtrackID, "limit is capped")
+
+	for _, limit := range []string{"0", "-1", "abc"} {
+		assert.Equal(t, http.StatusBadRequest, e.do(http.MethodGet, "/api/v1/statistics/soundtracks/most-played?limit="+limit).Code, limit)
+	}
+
+	var summary backend.StatisticsSummary
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/statistics/summary").Body.Bytes(), &summary))
+	assert.Equal(t, backend.StatisticsSummary{TotalSoundtracks: 5, AvgSoundtrackPlays: 1.5}, summary)
+
+	e.server.stats = backend.NewStatisticsService(statsStore{err: errors.New("db down")})
+	e.handler = e.server.RegisterRoutes()
+	assert.Equal(t, http.StatusInternalServerError, e.do(http.MethodGet, "/api/v1/statistics/summary").Code)
+}
diff --git a/internal/server/helpers_test.go b/internal/server/helpers_test.go
new file mode 100644
index 0000000..0a77e95
--- /dev/null
+++ b/internal/server/helpers_test.go
@@ -0,0 +1,120 @@
+package server
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync/atomic"
+	"testing"
+
+	"music-server/internal/config"
+	"music-server/internal/db/repository"
+	"music-server/internal/logging"
+	"music-server/internal/testutil/fakedb"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMain(m *testing.M) {
+	logging.Init("fatal", false)
+	os.Exit(m.Run())
+}
+
+type fakeDatabase struct {
+	closed  atomic.Bool
+	onClose func()
+}
+
+func (f *fakeDatabase) Health(context.Context) map[string]string {
+	return map[string]string{"status": "up"}
+}
+
+func (f *fakeDatabase) Close() {
+	if f.onClose != nil {
+		f.onClose()
+	}
+	f.closed.Store(true)
+}
+
+// testEnv is a Server backed by an in-memory database and temporary folders.
+type testEnv struct {
+	t       *testing.T
+	cfg     config.Config
+	store   *fakedb.Store
+	db      *fakeDatabase
+	server  *Server
+	handler http.Handler
+}
+
+func writeFile(t *testing.T, path, content string) {
+	t.Helper()
+	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0o755))
+	require.NoError(t, os.WriteFile(path, []byte(content), 0o644))
+}
+
+func newTestEnv(t *testing.T, configure ...func(*config.Config)) *testEnv {
+	t.Helper()
+	base := t.TempDir()
+	cfg := config.Config{
+		Port:               0,
+		MusicPath:          filepath.Join(base, "music"),
+		CharactersPath:     filepath.Join(base, "characters"),
+		SoundCheckPath:     filepath.Join(base, "songs"),
+		FrontendPath:       filepath.Join(base, "frontend"),
+		DisableSessionAuth: true,
+		ReleasesURL:        "http://127.0.0.1:1",
+	}
+	for _, c := range configure {
+		c(&cfg)
+	}
+	writeFile(t, filepath.Join(cfg.CharactersPath, "Adol.png"), "png")
+	writeFile(t, filepath.Join(cfg.CharactersPath, "Aloy.jpg"), "jpg")
+	writeFile(t, filepath.Join(base, "secret.png"), "secret")
+	writeFile(t, filepath.Join(cfg.SoundCheckPath, "check.mp3"), "sound check")
+	writeFile(t, filepath.Join(cfg.FrontendPath, "index.html"), "<html>frontend</html>")
+
+	store := fakedb.New()
+	database := &fakeDatabase{}
+	s, err := New(cfg, store, database)
+	require.NoError(t, err)
+	t.Cleanup(func() { s.sync.Wait(); s.characters.Close() })
+	return &testEnv{t: t, cfg: cfg, store: store, db: database, server: s, handler: s.httpServer.Handler}
+}
+
+// addSong creates a song file and its database rows.
+func (e *testEnv) addSong(soundtrack, song, content string) repository.Song {
+	e.t.Helper()
+	dir := e.cfg.MusicPath + "/" + soundtrack + "/"
+	fileName := song + ".mp3"
+	writeFile(e.t, dir+fileName, content)
+	st, ok := e.store.Soundtrack(soundtrack)
+	if !ok {
+		st = e.store.AddSoundtrack(repository.Soundtrack{SoundtrackName: soundtrack, Path: dir})
+	}
+	return e.store.AddTestSong(repository.Song{SoundtrackID: st.ID, SongName: song, Path: dir + fileName, FileName: &fileName})
+}
+
+func (e *testEnv) do(method, path string, headers ...string) *httptest.ResponseRecorder {
+	return e.doBody(method, path, "", headers...)
+}
+
+func (e *testEnv) doBody(method, path, body string, headers ...string) *httptest.ResponseRecorder {
+	var reader io.Reader
+	if body != "" {
+		reader = strings.NewReader(body)
+	}
+	req := httptest.NewRequest(method, path, reader)
+	if body != "" {
+		req.Header.Set("Content-Type", "application/json")
+	}
+	for i := 0; i+1 < len(headers); i += 2 {
+		req.Header.Set(headers[i], headers[i+1])
+	}
+	rec := httptest.NewRecorder()
+	e.handler.ServeHTTP(rec, req)
+	return rec
+}
diff --git a/internal/server/routes_test.go b/internal/server/routes_test.go
new file mode 100644
index 0000000..3811d15
--- /dev/null
+++ b/internal/server/routes_test.go
@@ -0,0 +1,191 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"net"
+	"net/http"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"music-server/internal/backend"
+	"music-server/internal/config"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// blockSync replaces the sync service with one that keeps running until the returned function is called.
+func (e *testEnv) blockSync() (release func()) {
+	ch := make(chan struct{})
+	e.server.sync = backend.NewSyncService(e.store, e.cfg.MusicPath, func(context.Context) { <-ch })
+	e.handler = e.server.RegisterRoutes()
+	return func() { close(ch); e.server.sync.Wait() }
+}
+
+func TestDestructiveSyncEndpointsIgnoreGet(t *testing.T) {
+	e := newTestEnv(t)
+	e.addSong("Game A", "Song", "a")
+	for _, prefix := range []string{"", "/api/v1"} {
+		for _, path := range []string{"/sync", "/sync/new", "/sync/quick", "/sync/full", "/sync/new/full", "/sync/reset"} {
+			// GET falls through to the frontend's static files, which answer 404.
+			assert.Equal(t, http.StatusNotFound, e.do(http.MethodGet, prefix+path).Code, prefix+path)
+		}
+	}
+	assert.False(t, e.server.sync.IsSyncing(), "no sync was started")
+	assert.Len(t, e.store.Songs, 1, "nothing was deleted")
+}
+
+func TestSyncStartAndLock(t *testing.T) {
+	for _, prefix := range []string{"", "/api/v1"} {
+		t.Run("prefix="+prefix, func(t *testing.T) {
+			e := newTestEnv(t)
+			e.addSong("Game A", "Song", "a")
+			release := e.blockSync()
+
+			assert.Equal(t, http.StatusOK, e.do(http.MethodPost, prefix+"/sync").Code)
+			assert.Equal(t, http.StatusLocked, e.do(http.MethodPost, prefix+"/sync/full").Code)
+			assert.Equal(t, http.StatusLocked, e.do(http.MethodPost, prefix+"/sync/reset").Code)
+			assert.Equal(t, http.StatusLocked, e.do(http.MethodGet, prefix+"/music/rand").Code)
+			assert.Equal(t, http.StatusOK, e.do(http.MethodGet, prefix+"/music/info").Code, "info is available during sync")
+
+			progress := e.do(http.MethodGet, prefix+"/sync/progress")
+			assert.Equal(t, http.StatusOK, progress.Code)
+			assert.Contains(t, progress.Body.String(), `"progress"`)
+
+			release()
+			assert.Equal(t, http.StatusOK, e.do(http.MethodGet, prefix+"/music/all").Code)
+			result := e.do(http.MethodGet, prefix+"/sync/progress")
+			assert.Contains(t, result.Body.String(), `"total_time"`)
+		})
+	}
+}
+
+func TestSyncResetEndpoint(t *testing.T) {
+	e := newTestEnv(t)
+	e.addSong("Game A", "Song", "a")
+	assert.Equal(t, http.StatusOK, e.do(http.MethodPost, "/sync/reset").Code)
+	assert.Empty(t, e.store.Soundtracks)
+	assert.Empty(t, e.store.Songs)
+}
+
+func TestLegacyRoutesAreDeprecated(t *testing.T) {
+	e := newTestEnv(t)
+	rec := e.do(http.MethodGet, "/version")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "true", rec.Header().Get("Deprecation"))
+
+	rec = e.do(http.MethodGet, "/api/v1/version")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Empty(t, rec.Header().Get("Deprecation"))
+}
+
+func TestVersionEndpoints(t *testing.T) {
+	e := newTestEnv(t)
+	var latest backend.VersionData
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/version").Body.Bytes(), &latest))
+	assert.Equal(t, backend.GetLatestVersion(), latest)
+
+	var history []backend.VersionData
+	require.NoError(t, json.Unmarshal(e.do(http.MethodGet, "/api/v1/version/history").Body.Bytes(), &history))
+	assert.Equal(t, backend.GetVersionHistory(), history)
+}
+
+func TestHealthEndpoint(t *testing.T) {
+	e := newTestEnv(t)
+	rec := e.do(http.MethodGet, "/health")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.JSONEq(t, `{"status":"up"}`, rec.Body.String())
+}
+
+func TestOpenAPIAndSwagger(t *testing.T) {
+	e := newTestEnv(t)
+
+	for _, path := range []string{"/openapi", "/swagger/doc.json"} {
+		rec := e.do(http.MethodGet, path)
+		require.Equal(t, http.StatusOK, rec.Code, path)
+		var spec struct {
+			Paths map[string]map[string]any `json:"paths"`
+		}
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &spec), path)
+		assert.Contains(t, spec.Paths, "/api/v1/token", path)
+		assert.Contains(t, spec.Paths["/sync/reset"], "post", path)
+	}
+
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/swagger/index.html").Code)
+}
+
+func TestSearchPageAndFrontend(t *testing.T) {
+	e := newTestEnv(t)
+	e.addSong("Kingdom Hearts", "Dearly Beloved", "x")
+
+	assert.Equal(t, http.StatusOK, e.do(http.MethodGet, "/search").Code)
+	rec := e.do(http.MethodPost, "/find")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Contains(t, rec.Body.String(), "Kingdom Hearts")
+
+	rec = e.do(http.MethodGet, "/")
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Contains(t, rec.Body.String(), "frontend")
+}
+
+func TestShutdownWaitsForRequestsBeforeClosingDatabase(t *testing.T) {
+	e := newTestEnv(t)
+	started := make(chan struct{})
+	release := make(chan struct{})
+	var requestDone atomic.Bool
+	e.server.httpServer.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		close(started)
+		<-release
+		requestDone.Store(true)
+	})
+	var closedAfterRequest atomic.Bool
+	e.db.onClose = func() { closedAfterRequest.Store(requestDone.Load()) }
+
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	require.NoError(t, err)
+	go e.server.httpServer.Serve(ln)
+
+	responded := make(chan error, 1)
+	go func() {
+		resp, err := http.Get("http://" + ln.Addr().String())
+		if err == nil {
+			resp.Body.Close()
+		}
+		responded <- err
+	}()
+	<-started
+
+	shutdownDone := make(chan error, 1)
+	go func() { shutdownDone <- e.server.Shutdown(context.Background()) }()
+
+	time.Sleep(50 * time.Millisecond)
+	assert.False(t, e.db.closed.Load(), "database must stay open while a request is running")
+
+	close(release)
+	require.NoError(t, <-responded)
+	require.NoError(t, <-shutdownDone)
+	assert.True(t, e.db.closed.Load())
+	assert.True(t, closedAfterRequest.Load())
+}
+
+func TestTrustedProxies(t *testing.T) {
+	// Without trusted proxies the forwarded header is ignored, so all requests share one bucket.
+	e := newTestEnv(t)
+	for i := range 10 {
+		e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0."+string(rune('0'+i)))
+	}
+	assert.Equal(t, http.StatusTooManyRequests, e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.1.1").Code)
+
+	// httptest requests come from 192.0.2.1, which is trusted here.
+	e = newTestEnv(t, func(c *config.Config) {
+		_, trusted, _ := net.ParseCIDR("192.0.2.0/24")
+		c.TrustedProxies = []*net.IPNet{trusted}
+	})
+	for range 10 {
+		e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0.1")
+	}
+	assert.Equal(t, http.StatusTooManyRequests, e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0.1").Code)
+	assert.Equal(t, http.StatusOK, e.doBody(http.MethodPost, "/api/v1/token", `{}`, "X-Forwarded-For", "10.0.0.2").Code)
+}
diff --git a/internal/testutil/fakedb/fakedb.go b/internal/testutil/fakedb/fakedb.go
new file mode 100644
index 0000000..d5751b0
--- /dev/null
+++ b/internal/testutil/fakedb/fakedb.go
@@ -0,0 +1,327 @@
+// Package fakedb provides an in-memory repository.Querier for tests.
+package fakedb
+
+import (
+	"cmp"
+	"context"
+	"math/rand/v2"
+	"slices"
+	"sync"
+	"time"
+
+	"music-server/internal/db/repository"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5"
+)
+
+// Store is an in-memory implementation of the queries used by the application.
+// Calling a query it does not implement panics through the nil embedded interface.
+type Store struct {
+	repository.Querier
+
+	mu          sync.Mutex
+	nextID      int32
+	Soundtracks []repository.Soundtrack
+	Songs       []repository.Song
+	Sessions    map[string]repository.Session
+
+	// Err, when set, is returned by every implemented query.
+	Err error
+}
+
+// New returns an empty Store.
+func New() *Store {
+	return &Store{Sessions: map[string]repository.Session{}}
+}
+
+func (s *Store) lock() func() {
+	s.mu.Lock()
+	return s.mu.Unlock
+}
+
+// AddSoundtrack inserts a soundtrack and returns it with its ID and UUID set.
+func (s *Store) AddSoundtrack(st repository.Soundtrack) repository.Soundtrack {
+	defer s.lock()()
+	s.nextID++
+	st.ID = s.nextID
+	if st.Uuid == uuid.Nil {
+		st.Uuid = uuid.New()
+	}
+	s.Soundtracks = append(s.Soundtracks, st)
+	return st
+}
+
+// AddTestSong inserts a song and returns it with its UUID set.
+func (s *Store) AddTestSong(song repository.Song) repository.Song {
+	defer s.lock()()
+	if song.Uuid == uuid.Nil {
+		song.Uuid = uuid.New()
+	}
+	s.Songs = append(s.Songs, song)
+	return song
+}
+
+// Soundtrack returns the soundtrack with the given name.
+func (s *Store) Soundtrack(name string) (repository.Soundtrack, bool) {
+	defer s.lock()()
+	for _, st := range s.Soundtracks {
+		if st.SoundtrackName == name {
+			return st, true
+		}
+	}
+	return repository.Soundtrack{}, false
+}
+
+// SongsOf returns the songs of a soundtrack sorted by path.
+func (s *Store) SongsOf(soundtrackID int32) []repository.Song {
+	defer s.lock()()
+	var songs []repository.Song
+	for _, song := range s.Songs {
+		if song.SoundtrackID == soundtrackID {
+			songs = append(songs, song)
+		}
+	}
+	slices.SortFunc(songs, func(a, b repository.Song) int { return cmp.Compare(a.Path, b.Path) })
+	return songs
+}
+
+func (s *Store) soundtrackIndex(id int32) int {
+	return slices.IndexFunc(s.Soundtracks, func(st repository.Soundtrack) bool { return st.ID == id })
+}
+
+func (s *Store) updateSoundtrack(id int32, f func(*repository.Soundtrack)) error {
+	defer s.lock()()
+	if s.Err != nil {
+		return s.Err
+	}
+	if i := s.soundtrackIndex(id); i >= 0 {
+		f(&s.Soundtracks[i])
+	}
+	return nil
+}
+
+func sortedByName(soundtracks []repository.Soundtrack) []repository.Soundtrack {
+	slices.SortFunc(soundtracks, func(a, b repository.Soundtrack) int { return cmp.Compare(a.SoundtrackName, b.SoundtrackName) })
+	return soundtracks
+}
+
+func (s *Store) FindAllSoundtracks(context.Context) ([]repository.Soundtrack, error) {
+	defer s.lock()()
+	if s.Err != nil {
+		return nil, s.Err
+	}
+	var active []repository.Soundtrack
+	for _, st := range s.Soundtracks {
+		if st.Deleted == nil {
+			active = append(active, st)
+		}
+	}
+	return sortedByName(active), nil
+}
+
+func (s *Store) GetAllSoundtracksIncludingDeleted(context.Context) ([]repository.Soundtrack, error) {
+	defer s.lock()()
+	if s.Err != nil {
+		return nil, s.Err
+	}
+	return sortedByName(slices.Clone(s.Soundtracks)), nil
+}
+
+func (s *Store) InsertSoundtrack(_ context.Context, arg repository.InsertSoundtrackParams) (repository.InsertSoundtrackRow, error) {
+	if s.Err != nil {
+		return repository.InsertSoundtrackRow{}, s.Err
+	}
+	st := s.AddSoundtrack(repository.Soundtrack{
+		SoundtrackName: arg.SoundtrackName,
+		Path:           arg.Path,
+		Hash:           arg.Hash,
+		Uuid:           arg.Uuid,
+		Added:          time.Now(),
+	})
+	return repository.InsertSoundtrackRow{ID: st.ID, Uuid: st.Uuid}, nil
+}
+
+func (s *Store) ResetSoundtrackIdSeq(context.Context) (int64, error) {
+	return int64(s.nextID), s.Err
+}
+
+func (s *Store) UpdateSoundtrackHash(_ context.Context, arg repository.UpdateSoundtrackHashParams) error {
+	return s.updateSoundtrack(arg.ID, func(st *repository.Soundtrack) { st.Hash = arg.Hash })
+}
+
+func (s *Store) UpdateSoundtrackName(_ context.Context, arg repository.UpdateSoundtrackNameParams) error {
+	return s.updateSoundtrack(arg.ID, func(st *repository.Soundtrack) { st.SoundtrackName, st.Path = arg.Name, arg.Path })
+}
+
+func (s *Store) SetSoundtrackFingerprint(_ context.Context, arg repository.SetSoundtrackFingerprintParams) error {
+	return s.updateSoundtrack(arg.ID, func(st *repository.Soundtrack) { st.Fingerprint = arg.Fingerprint })
+}
+
+func (s *Store) RemoveSoundtrackDeletionDate(_ context.Context, id int32) error {
+	return s.updateSoundtrack(id, func(st *repository.Soundtrack) { st.Deleted = nil })
+}
+
+func (s *Store) AddSoundtrackPlayed(_ context.Context, id int32) error {
+	now := time.Now()
+	return s.updateSoundtrack(id, func(st *repository.Soundtrack) { st.TimesPlayed++; st.LastPlayed = &now })
+}
+
+func (s *Store) MarkSoundtracksDeletedExcept(_ context.Context, ids []int32) error {
+	defer s.lock()()
+	if s.Err != nil {
+		return s.Err
+	}
+	now := time.Now()
+	for i := range s.Soundtracks {
+		if s.Soundtracks[i].Deleted == nil && !slices.Contains(ids, s.Soundtracks[i].ID) {
+			s.Soundtracks[i].Deleted = &now
+		}
+	}
+	return nil
+}
+
+func (s *Store) ClearSoundtracks(context.Context) error {
+	defer s.lock()()
+	s.Soundtracks = nil
+	return s.Err
+}
+
+func (s *Store) ClearSongs(context.Context) error {
+	defer s.lock()()
+	s.Songs = nil
+	return s.Err
+}
+
+func (s *Store) FindSongsFromSoundtrack(_ context.Context, soundtrackID int32) ([]repository.Song, error) {
+	if s.Err != nil {
+		return nil, s.Err
+	}
+	return s.SongsOf(soundtrackID), nil
+}
+
+func (s *Store) FetchAllSongs(context.Context) ([]repository.Song, error) {
+	defer s.lock()()
+	return slices.Clone(s.Songs), s.Err
+}
+
+func (s *Store) AddSong(_ context.Context, arg repository.AddSongParams) error {
+	if s.Err != nil {
+		return s.Err
+	}
+	s.AddTestSong(repository.Song{
+		SoundtrackID:   arg.SoundtrackID,
+		SongName:       arg.SongName,
+		Path:           arg.Path,
+		FileName:       arg.FileName,
+		Hash:           arg.Hash,
+		Uuid:           arg.Uuid,
+		SoundtrackUuid: arg.SoundtrackUuid,
+	})
+	return nil
+}
+
+func (s *Store) UpdateSongByUUID(_ context.Context, arg repository.UpdateSongByUUIDParams) error {
+	defer s.lock()()
+	for i := range s.Songs {
+		if s.Songs[i].Uuid == arg.Uuid {
+			s.Songs[i].SongName, s.Songs[i].FileName, s.Songs[i].Path, s.Songs[i].Hash = arg.SongName, arg.FileName, arg.Path, arg.Hash
+		}
+	}
+	return s.Err
+}
+
+func (s *Store) AddSongPlayed(_ context.Context, arg repository.AddSongPlayedParams) error {
+	defer s.lock()()
+	for i := range s.Songs {
+		if s.Songs[i].SoundtrackID == arg.SoundtrackID && s.Songs[i].SongName == arg.SongName {
+			s.Songs[i].TimesPlayed++
+		}
+	}
+	return s.Err
+}
+
+func (s *Store) RemoveBrokenSong(_ context.Context, arg repository.RemoveBrokenSongParams) error {
+	defer s.lock()()
+	s.Songs = slices.DeleteFunc(s.Songs, func(song repository.Song) bool {
+		return song.SoundtrackID == arg.SoundtrackID && song.Path == arg.Path
+	})
+	return s.Err
+}
+
+func (s *Store) RemoveBrokenSongs(_ context.Context, uuids []uuid.UUID) error {
+	defer s.lock()()
+	s.Songs = slices.DeleteFunc(s.Songs, func(song repository.Song) bool { return slices.Contains(uuids, song.Uuid) })
+	return s.Err
+}
+
+func (s *Store) GetRandomActiveSong(context.Context) (repository.GetRandomActiveSongRow, error) {
+	defer s.lock()()
+	if s.Err != nil {
+		return repository.GetRandomActiveSongRow{}, s.Err
+	}
+	var rows []repository.GetRandomActiveSongRow
+	for _, song := range s.Songs {
+		if i := s.soundtrackIndex(song.SoundtrackID); i >= 0 && s.Soundtracks[i].Deleted == nil {
+			rows = append(rows, repository.GetRandomActiveSongRow{Song: song, SoundtrackPath: s.Soundtracks[i].Path})
+		}
+	}
+	if len(rows) == 0 {
+		return repository.GetRandomActiveSongRow{}, pgx.ErrNoRows
+	}
+	return rows[rand.IntN(len(rows))], nil
+}
+
+func (s *Store) CreateSession(_ context.Context, arg repository.CreateSessionParams) (repository.Session, error) {
+	defer s.lock()()
+	if s.Err != nil {
+		return repository.Session{}, s.Err
+	}
+	session := repository.Session{
+		Token:      arg.Token,
+		IpAddress:  arg.IpAddress,
+		UserAgent:  arg.UserAgent,
+		ClientType: arg.ClientType,
+		ExpiresAt:  arg.ExpiresAt,
+	}
+	s.Sessions[arg.Token] = session
+	return session, nil
+}
+
+func (s *Store) GetSession(_ context.Context, token string) (repository.Session, error) {
+	defer s.lock()()
+	if s.Err != nil {
+		return repository.Session{}, s.Err
+	}
+	session, ok := s.Sessions[token]
+	if !ok {
+		return repository.Session{}, pgx.ErrNoRows
+	}
+	return session, nil
+}
+
+func (s *Store) DeleteSession(ctx context.Context, token string) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	defer s.lock()()
+	delete(s.Sessions, token)
+	return s.Err
+}
+
+func (s *Store) DeleteExpiredSessions(context.Context) error {
+	defer s.lock()()
+	for token, session := range s.Sessions {
+		if session.ExpiresAt.Time.Before(time.Now()) {
+			delete(s.Sessions, token)
+		}
+	}
+	return s.Err
+}
+
+// HasSession reports whether a session with the given token exists.
+func (s *Store) HasSession(token string) bool {
+	defer s.lock()()
+	_, ok := s.Sessions[token]
+	return ok
+}
diff --git a/internal/testutil/pgtest/pgtest.go b/internal/testutil/pgtest/pgtest.go
new file mode 100644
index 0000000..c95f916
--- /dev/null
+++ b/internal/testutil/pgtest/pgtest.go
@@ -0,0 +1,154 @@
+//go:build integration
+
+// Package pgtest starts a PostgreSQL container for integration tests.
+//
+// Use it from TestMain:
+//
+//	func TestMain(m *testing.M) { os.Exit(pgtest.Main(m)) }
+package pgtest
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"music-server/internal/db"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/testcontainers/testcontainers-go"
+	"github.com/testcontainers/testcontainers-go/wait"
+)
+
+const (
+	user     = "postgres"
+	password = "postgres"
+)
+
+var (
+	container testcontainers.Container
+	host      string
+	port      string
+	counter   atomic.Int32
+)
+
+// Main starts PostgreSQL, runs the tests and stops PostgreSQL again.
+func Main(m *testing.M) int {
+	ctx := context.Background()
+	c, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
+		ContainerRequest: testcontainers.ContainerRequest{
+			Image:        "postgres:15-alpine",
+			ExposedPorts: []string{"5432/tcp"},
+			Env:          map[string]string{"POSTGRES_USER": user, "POSTGRES_PASSWORD": password},
+			WaitingFor: wait.ForAll(
+				wait.ForLog("database system is ready to accept connections").WithOccurrence(2),
+				wait.ForListeningPort("5432/tcp"),
+			).WithDeadline(2 * time.Minute),
+		},
+		Started: true,
+	})
+	if err != nil {
+		log.Printf("failed to start PostgreSQL container (is Docker running?): %v", err)
+		return 1
+	}
+	defer func() {
+		if err := c.Terminate(ctx); err != nil {
+			log.Printf("failed to stop PostgreSQL container: %v", err)
+		}
+	}()
+
+	container = c
+	host, err = c.Host(ctx)
+	if err != nil {
+		log.Printf("failed to get container host: %v", err)
+		return 1
+	}
+	mapped, err := c.MappedPort(ctx, "5432/tcp")
+	if err != nil {
+		log.Printf("failed to get container port: %v", err)
+		return 1
+	}
+	port = mapped.Port()
+	return m.Run()
+}
+
+// ConnString returns the connection string for a database in the container.
+func ConnString(dbname string) string {
+	return db.ConnString(host, port, user, password, dbname)
+}
+
+// NewDatabase creates an empty database and returns its name. It is dropped when the test ends.
+func NewDatabase(t *testing.T) string {
+	t.Helper()
+	ctx := context.Background()
+	name := fmt.Sprintf("test_%d_%d", time.Now().UnixNano()%1_000_000, counter.Add(1))
+
+	admin, err := pgxpool.New(ctx, ConnString("postgres"))
+	if err != nil {
+		t.Fatalf("connect to postgres: %v", err)
+	}
+	defer admin.Close()
+	if _, err := admin.Exec(ctx, "CREATE DATABASE "+name); err != nil {
+		t.Fatalf("create database: %v", err)
+	}
+	t.Cleanup(func() {
+		admin, err := pgxpool.New(ctx, ConnString("postgres"))
+		if err != nil {
+			return
+		}
+		defer admin.Close()
+		admin.Exec(ctx, "DROP DATABASE IF EXISTS "+name+" WITH (FORCE)")
+	})
+	return name
+}
+
+// NewMigratedDatabase creates a database with all migrations applied.
+func NewMigratedDatabase(t *testing.T) *db.Database {
+	t.Helper()
+	database, err := db.NewDatabase(context.Background(), ConnString(NewDatabase(t)))
+	if err != nil {
+		t.Fatalf("open database: %v", err)
+	}
+	t.Cleanup(database.Close)
+	if err := database.RunMigrations(); err != nil {
+		t.Fatalf("run migrations: %v", err)
+	}
+	return database
+}
+
+// LoadSQLFile runs a SQL file with psql inside the container, as the superuser.
+func LoadSQLFile(t *testing.T, dbname, path string) {
+	t.Helper()
+	ctx := context.Background()
+	target := "/tmp/" + dbname + ".sql"
+	if err := container.CopyFileToContainer(ctx, path, target, 0o644); err != nil {
+		t.Fatalf("copy %s to container: %v", path, err)
+	}
+	code, reader, err := container.Exec(ctx, []string{"psql", "-U", user, "-d", dbname, "-v", "ON_ERROR_STOP=1", "-q", "-f", target})
+	if err != nil {
+		t.Fatalf("run psql: %v", err)
+	}
+	output, _ := io.ReadAll(reader)
+	if code != 0 {
+		t.Fatalf("psql exited with %d: %s", code, output)
+	}
+}
+
+// CreateRole creates a login role, used by dumps that reference their original owner.
+func CreateRole(t *testing.T, name string) {
+	t.Helper()
+	ctx := context.Background()
+	admin, err := pgxpool.New(ctx, ConnString("postgres"))
+	if err != nil {
+		t.Fatalf("connect to postgres: %v", err)
+	}
+	defer admin.Close()
+	_, err = admin.Exec(ctx, "CREATE ROLE "+name+" LOGIN")
+	if err != nil && !strings.Contains(err.Error(), "already exists") {
+		t.Fatalf("create role: %v", err)
+	}
+}
diff --git a/testMusic/A Bird Story/1. A Bird Story (Title Theme).mp3 b/testMusic/A Bird Story/1. A Bird Story (Title Theme).mp3
index 53b2e7d..3f6a8f6 100644
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diff --git a/testMusic/A Bird Story/2. Yesterday.mp3 b/testMusic/A Bird Story/2. Yesterday.mp3
index 55a332d..34be5f0 100644
Binary files a/testMusic/A Bird Story/2. Yesterday.mp3 and b/testMusic/A Bird Story/2. Yesterday.mp3 differ
diff --git a/testMusic/A Bird Story/3. Yesterday (Reversing).mp3 b/testMusic/A Bird Story/3. Yesterday (Reversing).mp3
index f9cb622..5142bdf 100644
Binary files a/testMusic/A Bird Story/3. Yesterday (Reversing).mp3 and b/testMusic/A Bird Story/3. Yesterday (Reversing).mp3 differ
diff --git a/testMusic/A Bird Story/38. Bestest Detectives in the World - Winter Vers. (Holiday Special).mp3 b/testMusic/A Bird Story/38. Bestest Detectives in the World - Winter Vers. (Holiday Special).mp3
index b5ac107..24ffd79 100644
Binary files a/testMusic/A Bird Story/38. Bestest Detectives in the World - Winter Vers. (Holiday Special).mp3 and b/testMusic/A Bird Story/38. Bestest Detectives in the World - Winter Vers. (Holiday Special).mp3 differ
diff --git a/testMusic/A Bird Story/39. To the Moon - For River - Minigame Vers. (Holiday Special).mp3 b/testMusic/A Bird Story/39. To the Moon - For River - Minigame Vers. (Holiday Special).mp3
index 131b390..6183d25 100644
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diff --git a/testMusic/A Bird Story/40. A Bird Story (Piano).mp3 b/testMusic/A Bird Story/40. A Bird Story (Piano).mp3
index 605ec72..0a14ad5 100644
Binary files a/testMusic/A Bird Story/40. A Bird Story (Piano).mp3 and b/testMusic/A Bird Story/40. A Bird Story (Piano).mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 01 Alicia.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 01 Alicia.mp3
index d010d9f..593bba1 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 01 Alicia.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 01 Alicia.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 02 Gustave.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 02 Gustave.mp3
index 3d83d5b..bb9078d 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 02 Gustave.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 02 Gustave.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 03 Lumière.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 03 Lumière.mp3
index bf8cbb9..2e9064a 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 03 Lumière.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 03 Lumière.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 144 Renoir.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 144 Renoir.mp3
index 68356dc..6bc3898 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 144 Renoir.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 144 Renoir.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 145 Une vie à peindre.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 145 Une vie à peindre.mp3
index 2f4bf72..773398a 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 145 Une vie à peindre.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 145 Une vie à peindre.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 152 Une vie à rêver.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 152 Une vie à rêver.mp3
index 7cd5ac2..2142c89 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 152 Une vie à rêver.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 152 Une vie à rêver.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 22 Lune.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 22 Lune.mp3
index 3a85c51..50017ac 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 22 Lune.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 22 Lune.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 28 Flying Waters - Electric Tides.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 28 Flying Waters - Electric Tides.mp3
index b43c095..08cddce 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 28 Flying Waters - Electric Tides.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 28 Flying Waters - Electric Tides.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 60 Une vie à t'aimer.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 60 Une vie à t'aimer.mp3
index bfe8496..b721fb1 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 60 Une vie à t'aimer.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 60 Une vie à t'aimer.mp3 differ
diff --git a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 77 Monoco.mp3 b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 77 Monoco.mp3
index 4aea612..fb0248d 100644
Binary files a/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 77 Monoco.mp3 and b/testMusic/Clair Obscur - Expedition 33/Clair Obscur- Expedition 33 - 77 Monoco.mp3 differ
diff --git a/testMusic/Metal Gear Rising - Revengeance/01 - Rules of Nature (Platinum Mix).mp3 b/testMusic/Metal Gear Rising - Revengeance/01 - Rules of Nature (Platinum Mix).mp3
index 10a4a33..7cc906b 100644
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diff --git a/testMusic/Metal Gear Rising - Revengeance/04 - I'm My Own Master Now (Platinum Mix).mp3 b/testMusic/Metal Gear Rising - Revengeance/04 - I'm My Own Master Now (Platinum Mix).mp3
index 78ea663..51ad82d 100644
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diff --git a/testMusic/Metal Gear Rising - Revengeance/05 - A Stranger I Remain (Maniac Agenda Mix).mp3 b/testMusic/Metal Gear Rising - Revengeance/05 - A Stranger I Remain (Maniac Agenda Mix).mp3
index 459399e..de09086 100644
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diff --git a/testMusic/Metal Gear Rising - Revengeance/08 - Red Sun (Maniac Agenda Mix).mp3 b/testMusic/Metal Gear Rising - Revengeance/08 - Red Sun (Maniac Agenda Mix).mp3
index eedc15f..261990b 100644
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diff --git a/testMusic/Metal Gear Rising - Revengeance/09 - A Soul Can't Be Cut (Platinum Mix).mp3 b/testMusic/Metal Gear Rising - Revengeance/09 - A Soul Can't Be Cut (Platinum Mix).mp3
index b848e31..88f493e 100644
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diff --git a/testMusic/Metal Gear Rising - Revengeance/11 - It Has to Be This Way (Platinum Mix).mp3 b/testMusic/Metal Gear Rising - Revengeance/11 - It Has to Be This Way (Platinum Mix).mp3
index 44afa40..a9c4f5e 100644
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diff --git a/testMusic/Metal Gear Rising - Revengeance/12 - The War Still Rages Within.mp3 b/testMusic/Metal Gear Rising - Revengeance/12 - The War Still Rages Within.mp3
index b9e693f..92224a8 100644
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