feat: implement 1B domain entities/repos + 1H library API routes

1B — domain layer:
- New entities: Album, Playlist, Like, PlayHistoryEntry
- Track entity extended with album_id, genre, year fields
- New protocols: AlbumRepository, PlaylistRepository, LikeRepository, HistoryRepository
- ArtistRepository / TrackRepository protocols extended (list, count, update, get_many, etc.)
- New repos: SqlAlchemyAlbum/Playlist/Like/HistoryRepository
- Artist and track repos updated to match extended protocols

1H — library API:
- Pagination: PagedResponse[T] generic, offset-based, limit default 50 max 200
- Schemas: TrackOut, AlbumOut, ArtistOut, PlaylistOut/Create/Update,
  LikeEvent/State, HistoryIn/Out, LibrarySearchResponse
- GET/PATCH/DELETE /tracks with filters, sort, pagination
- GET /albums, /albums/{id}, /albums/{id}/tracks
- GET /artists, /artists/{id}, /artists/{id}/albums, /artists/{id}/tracks
- GET /search/library (ILIKE across tracks/albums/artists)
- Full /playlists CRUD + track add/remove (append-only version bump)
- POST /likes (append-only event log), GET /likes, GET /likes/state
- POST /history (scrobble), GET /history
- deps.py: TrackRepoDep, ArtistRepoDep, AlbumRepoDep, PlaylistRepoDep,
  LikeRepoDep, HistoryRepoDep

ruff ✅  mypy ✅  pytest 45/45 ✅

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/v1/history.py

@@ -1,15 +1,52 @@
 """Playback history endpoints."""
 
-from typing import Any
+from fastapi import APIRouter, Query, Response
 
-from fastapi import APIRouter
+from app.api.deps import CurrentUser, HistoryRepoDep, TrackRepoDep
+from app.api.schemas.history import HistoryIn, HistoryOut
+from app.api.schemas.pagination import PagedResponse
+from app.domain.errors import NotFoundError
 
 router = APIRouter(prefix="/history", tags=["history"])
 
 
+@router.post("", status_code=204)
+async def record_history(
+    body: HistoryIn,
+    history_repo: HistoryRepoDep,
+    track_repo: TrackRepoDep,
+    user: CurrentUser,
+) -> Response:
+    track = await track_repo.get_by_id(body.track_id)
+    if track is None:
+        raise NotFoundError(f"Track {body.track_id} not found.")
+    await history_repo.add(
+        user_id=user.id,
+        track_id=body.track_id,
+        played_at=body.played_at,
+        play_duration_seconds=body.play_duration_seconds,
+        completed=body.completed,
+    )
+    return Response(status_code=204)
+
+
 @router.get("")
-async def get_history() -> Any: ...
-
-
-@router.post("")
-async def record_history() -> Any: ...
+async def get_history(
+    history_repo: HistoryRepoDep,
+    user: CurrentUser,
+    limit: int = Query(50, ge=1, le=200),
+    offset: int = Query(0, ge=0),
+) -> PagedResponse[HistoryOut]:
+    entries = await history_repo.list(user_id=user.id, limit=limit, offset=offset)
+    total = await history_repo.count(user_id=user.id)
+    items = [
+        HistoryOut(
+            id=e.id,
+            track_id=e.track_id,
+            played_at=e.played_at,
+            play_duration_seconds=e.play_duration_seconds,
+            completed=e.completed,
+        )
+        for e in entries
+    ]
+    return PagedResponse(items=items, total=total, limit=limit, offset=offset)