Save best scores and last difficulty to a JSON profile

- profile package: best moves, best time and games played per
  deck/difficulty, stored in the user data folder
- Win panel shows the best (or New best!), language menu shows bests
- Profile memory always comes from the heap allocator (it outlives callers)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/profile_test.odin

@@ -0,0 +1,70 @@
+package tests
+
+import "core:os"
+import "core:testing"
+import memory "../src/memory"
+import profile "../src/profile"
+
+@(test)
+record_game_tracks_bests :: proc(t: ^testing.T) {
+    key := "TEST/RECORD"
+    first := profile.record_game(key, 20, 90)
+    testing.expect_value(t, first.record.games, 1)
+    testing.expect_value(t, first.record.best_moves, 20)
+    testing.expect(t, !first.new_best_moves && !first.new_best_time) // nothing to beat yet
+
+    worse := profile.record_game(key, 25, 120)
+    testing.expect(t, !worse.new_best_moves && !worse.new_best_time)
+    testing.expect_value(t, worse.record.best_moves, 20)
+
+    // Fewer moves but slower: only the moves record changes
+    fewer := profile.record_game(key, 15, 100)
+    testing.expect(t, fewer.new_best_moves && !fewer.new_best_time)
+    testing.expect_value(t, fewer.record.best_moves, 15)
+    testing.expect_value(t, fewer.record.best_seconds, 90)
+    testing.expect_value(t, fewer.record.games, 3)
+}
+
+@(test)
+profile_round_trips_through_json :: proc(t: ^testing.T) {
+    path := "build/test-profile.json"
+    os.remove(path)
+    defer os.remove(path)
+
+    testing.expect(t, profile.init(path))
+    defer profile.path = "" // stop other tests from writing the file
+    profile.set_difficulty("HARD")
+    profile.record_game("TEST/SAVE", 12, 61.5)
+
+    // Reload from disk into a clean state
+    profile.data = {}
+    testing.expect(t, profile.init(path))
+    testing.expect_value(t, profile.data.difficulty, "HARD")
+    record, ok := profile.get("TEST/SAVE")
+    testing.expect(t, ok)
+    testing.expect_value(t, record.best_moves, 12)
+    testing.expect_value(t, record.best_seconds, 61.5)
+}
+
+@(test)
+winning_records_a_score :: proc(t: ^testing.T) {
+    memory.deal(.KATAKANA, .EASY)
+    for i in 0 ..< memory.card_count {
+        if memory.cards[i].matched { continue }
+        memory.select_card(i)
+        memory.select_card(partner_of(i))
+        advance(2)
+    }
+    testing.expect_value(t, memory.state, memory.State.OVER)
+    record, ok := profile.get(memory.score_key(.KATAKANA, .EASY))
+    testing.expect(t, ok)
+    testing.expect_value(t, record.best_moves, memory.pair_count)
+    testing.expect_value(t, memory.last_result.record.games, record.games)
+}
+
+@(test)
+time_format :: proc(t: ^testing.T) {
+    testing.expect_value(t, profile.format_time(0), "0:00")
+    testing.expect_value(t, profile.format_time(65.9), "1:05")
+    testing.expect_value(t, profile.format_time(600), "10:00")
+}