feat(charts): сбор статистики проигрываний и API чартов

- модели Track / TrackPlay / TrackLike (+ миграция add_charts)
- сбор проигрываний в now-playing-поллере: при смене трека на станции
  пишется TrackPlay (нормализация artist+song -> Track), fire-and-forget
  обогащение через MusicBrainz (album/releaseDate)
- ChartsModule: GET /charts/tracks (период day/week/month/all, ранг, тренд,
  проигрывания, станции, лайки), GET /charts/tracks/:id (метрики, таймлайны
  популярности и лайков по дням, топ станций, isLiked), POST/DELETE like
- OptionalAuthGuard для публичной детальной страницы с опц. userId

prisma/migrations/20250602130000_add_charts/migration.sql

@@ -0,0 +1,68 @@
+-- CreateTable: tracks
+CREATE TABLE "tracks" (
+    "id"           TEXT        NOT NULL,
+    "norm_key"     TEXT        NOT NULL,
+    "artist"       TEXT        NOT NULL,
+    "song"         TEXT        NOT NULL,
+    "cover_url"    TEXT,
+    "album"        TEXT,
+    "release_date" TIMESTAMPTZ,
+    "first_seen_at" TIMESTAMPTZ NOT NULL DEFAULT now(),
+    "enriched_at"  TIMESTAMPTZ,
+
+    CONSTRAINT "tracks_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable: track_plays
+CREATE TABLE "track_plays" (
+    "id"         TEXT        NOT NULL,
+    "track_id"   TEXT        NOT NULL,
+    "station_id" TEXT        NOT NULL,
+    "played_at"  TIMESTAMPTZ NOT NULL DEFAULT now(),
+
+    CONSTRAINT "track_plays_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable: track_likes
+CREATE TABLE "track_likes" (
+    "id"         TEXT        NOT NULL,
+    "track_id"   TEXT        NOT NULL,
+    "user_id"    TEXT        NOT NULL,
+    "created_at" TIMESTAMPTZ NOT NULL DEFAULT now(),
+
+    CONSTRAINT "track_likes_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "tracks_norm_key_key" ON "tracks"("norm_key");
+
+-- CreateIndex
+CREATE INDEX "track_plays_track_id_played_at_idx" ON "track_plays"("track_id", "played_at");
+
+-- CreateIndex
+CREATE INDEX "track_plays_played_at_idx" ON "track_plays"("played_at");
+
+-- CreateIndex
+CREATE INDEX "track_plays_station_id_idx" ON "track_plays"("station_id");
+
+-- CreateIndex
+CREATE UNIQUE INDEX "track_likes_track_id_user_id_key" ON "track_likes"("track_id", "user_id");
+
+-- CreateIndex
+CREATE INDEX "track_likes_track_id_idx" ON "track_likes"("track_id");
+
+-- AddForeignKey
+ALTER TABLE "track_plays" ADD CONSTRAINT "track_plays_track_id_fkey"
+    FOREIGN KEY ("track_id") REFERENCES "tracks"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "track_plays" ADD CONSTRAINT "track_plays_station_id_fkey"
+    FOREIGN KEY ("station_id") REFERENCES "stations"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "track_likes" ADD CONSTRAINT "track_likes_track_id_fkey"
+    FOREIGN KEY ("track_id") REFERENCES "tracks"("id") ON DELETE CASCADE ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "track_likes" ADD CONSTRAINT "track_likes_user_id_fkey"
+    FOREIGN KEY ("user_id") REFERENCES "users"("id") ON DELETE CASCADE ON UPDATE CASCADE;