Add a small, tested base for all three clients, and Gitea CI/release workflows

internal/client (new): a typed Go HTTP client for the API - login,
register, logout, me, and full CRUD for games/platforms - shared by the
TUI and the Fyne GUI so request-building, auth and error handling (an
APIError with the HTTP status) live in one tested place instead of being
duplicated. 8 tests against an httptest server covering success, 401, 403
and that the token is stored/cleared at the right times.

cmd/tui (rewrite): drops the old unauthenticated read-only viewer. Now a
login screen (bubbles/textinput) -> a scrollable games table
(bubbles/table) with 'r' to refresh, built as an explicit state machine
(screenLogin/screenLoading/screenGames) so Update's transitions are
testable without a real terminal. 9 tests driving Update() directly.

cmd/gui (rewrite): drops raylib for Fyne. Same shape as the TUI - a login
form, then a games table, with networking on a goroutine and fyne.Do for
the UI updates. The table-cell and login-validation logic are plain
functions with no Fyne/display dependency, so they're tested directly (7
tests) rather than needing Fyne's headless test driver.

internal/api: tagged every operation (Auth/Platforms/Games/Misc) so the
generated OpenAPI spec groups into named services instead of one bucket;
api/openapi.json regenerated. Added CORS middleware (wildcard origin, no
credentials needed since clients use a bearer token, not the cookie) -
needed for the new web client's browser requests to the API's a different
origin.

web/ (new): an Angular 22 + Material app, API client generated from
api/openapi.json via ng-openapi-gen (services: true for per-resource
classes - AuthService/GamesService/PlatformsService - instead of one
generic Api facade). A Session service holds the token/user as signals,
persists the token to localStorage, and is the only thing that calls the
generated AuthService; an HttpInterceptorFn attaches the bearer token to
every request; a CanActivateFn guard protects /games. Login and Games are
standalone, lazy-loaded route components. 21 tests (Vitest, Angular's new
default - no browser/Karma needed) covering the service, interceptor,
guard and both components, run via `npm test` exactly as CI will call it.

Justfile: fixed run-tui/run-gui, which used `go run .../main.go` - broken
now that both packages span multiple files, since that only compiles the
one named file. Added web-install/web-dev/web-build/web-test.

.gitea/workflows/ci.yml (moved from .github, which Gitea doesn't read):
on push to main/develop - gofmt, go vet, go build, go test, go mod tidy
diff (with the Fyne build's system deps installed), sqlc diff, and the
web app's build+test.

.gitea/workflows/release.yml (new): on a vX.Y.Z tag, cross-compiles
api+tui for linux/darwin/windows (amd64+arm64, pure Go, no cgo), builds
the Fyne GUI for linux/amd64 only (cgo + its OpenGL/X11 link means it
can't cross-compile from one Linux runner the way api/tui do, and this
repo has no registered macOS/Windows runner to build it on natively -
documented in the workflow's comments), builds the web app, and creates a
Gitea release with all of it attached via the Gitea API. Written to
Gitea's documented GitHub-Actions-compatible syntax but not executable
from here - there's no Gitea server in this environment to run it
against, unlike everything else in this commit, which was.

Verified: every Go package builds/vets/tests clean; sqlc diff and go mod
tidy -diff are clean; the Angular app builds for production and its test
suite passes via `npm test`/`npm run build` (the exact commands CI runs),
including after a clean `npm ci` from the committed lockfile; the new CORS
config was checked with real preflight and GET requests against a running
server, not just read.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -0,0 +1,81 @@
+name: CI
+
+on:
+  push:
+    branches: [main, develop]
+
+jobs:
+  go:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      # cmd/gui (Fyne) uses cgo and links against the system's OpenGL/X11
+      # libraries, so building or testing ./... needs these present even
+      # though the GUI itself never opens a window in CI.
+      - name: Install system dependencies for the Fyne GUI build
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libgl1-mesa-dev xorg-dev
+
+      - name: gofmt
+        run: |
+          fmt_out="$(gofmt -l .)"
+          if [ -n "$fmt_out" ]; then
+            echo "The following files are not gofmt'd:"
+            echo "$fmt_out"
+            exit 1
+          fi
+
+      - name: go vet
+        run: go vet ./...
+
+      - name: go build
+        run: go build ./...
+
+      - name: go test
+        run: go test ./...
+
+      - name: go mod tidy (no diff expected)
+        run: |
+          go mod tidy
+          git diff --exit-code -- go.mod go.sum
+
+  sqlc:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: sqlc-dev/setup-sqlc@v4
+        with:
+          sqlc-version: "1.31.1"
+
+      - name: sqlc diff (generated code must match the schema/queries)
+        run: sqlc diff
+
+  web:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: web
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
+          cache-dependency-path: web/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build
+
+      - name: Test
+        run: npm test