feat(api): SessionRepository, session/song schemas with tags

Adds RehearsalSessionRepository (get_or_create, list_for_band with
counts, get_with_songs). Adds RehearsalSession schemas (Read, Detail,
Update). Extends SongRead/SongUpdate with tags and session_id fields.

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

api/src/rehearsalhub/repositories/rehearsal_session.py

@@ -0,0 +1,69 @@
+from __future__ import annotations
+
+import uuid
+from datetime import date, datetime
+
+from sqlalchemy import func, select
+from sqlalchemy.orm import selectinload
+
+from rehearsalhub.db.models import RehearsalSession, Song
+from rehearsalhub.repositories.base import BaseRepository
+
+
+class RehearsalSessionRepository(BaseRepository[RehearsalSession]):
+    model = RehearsalSession
+
+    async def get_by_nc_folder(self, band_id: uuid.UUID, nc_folder_path: str) -> RehearsalSession | None:
+        stmt = select(RehearsalSession).where(
+            RehearsalSession.band_id == band_id,
+            RehearsalSession.nc_folder_path == nc_folder_path,
+        )
+        result = await self.session.execute(stmt)
+        return result.scalar_one_or_none()
+
+    async def get_by_band_and_date(self, band_id: uuid.UUID, session_date: date) -> RehearsalSession | None:
+        # Match on date portion only (stored as DateTime(timezone=False))
+        day_start = datetime(session_date.year, session_date.month, session_date.day)
+        stmt = select(RehearsalSession).where(
+            RehearsalSession.band_id == band_id,
+            RehearsalSession.date == day_start,
+        )
+        result = await self.session.execute(stmt)
+        return result.scalar_one_or_none()
+
+    async def get_or_create(
+        self,
+        band_id: uuid.UUID,
+        session_date: date,
+        nc_folder_path: str,
+    ) -> RehearsalSession:
+        existing = await self.get_by_band_and_date(band_id, session_date)
+        if existing is not None:
+            return existing
+        return await self.create(
+            band_id=band_id,
+            date=datetime(session_date.year, session_date.month, session_date.day),
+            nc_folder_path=nc_folder_path,
+        )
+
+    async def list_for_band(self, band_id: uuid.UUID) -> list[tuple[RehearsalSession, int]]:
+        """Return (session, recording_count) tuples, newest date first."""
+        count_col = func.count(Song.id).label("recording_count")
+        stmt = (
+            select(RehearsalSession, count_col)
+            .outerjoin(Song, Song.session_id == RehearsalSession.id)
+            .where(RehearsalSession.band_id == band_id)
+            .group_by(RehearsalSession.id)
+            .order_by(RehearsalSession.date.desc())
+        )
+        result = await self.session.execute(stmt)
+        return [(row[0], row[1]) for row in result.all()]
+
+    async def get_with_songs(self, session_id: uuid.UUID) -> RehearsalSession | None:
+        stmt = (
+            select(RehearsalSession)
+            .options(selectinload(RehearsalSession.songs).selectinload(Song.versions))
+            .where(RehearsalSession.id == session_id)
+        )
+        result = await self.session.execute(stmt)
+        return result.scalar_one_or_none()

api/src/rehearsalhub/schemas/rehearsal_session.py

@@ -0,0 +1,27 @@
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, ConfigDict
+
+from rehearsalhub.schemas.song import SongRead
+
+
+class RehearsalSessionRead(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+    id: uuid.UUID
+    band_id: uuid.UUID
+    date: datetime
+    nc_folder_path: str | None = None
+    label: str | None = None
+    notes: str | None = None
+    created_at: datetime
+    recording_count: int = 0
+
+
+class RehearsalSessionDetail(RehearsalSessionRead):
+    songs: list[SongRead] = []
+
+
+class RehearsalSessionUpdate(BaseModel):
+    label: str | None = None
+    notes: str | None = None

api/src/rehearsalhub/schemas/song.py

@@ -15,6 +15,7 @@ class SongUpdate(BaseModel):
     title: str | None = None
     status: Literal["jam", "wip", "arranged", "recorded", "released"] | None = None
     notes: str | None = None
+    tags: list[str] | None = None
     global_key: str | None = None
     global_bpm: float | None = None
 
@@ -23,8 +24,10 @@ class SongRead(BaseModel):
     model_config = ConfigDict(from_attributes=True)
     id: uuid.UUID
     band_id: uuid.UUID
+    session_id: uuid.UUID | None = None
     title: str
     status: str
+    tags: list[str] = []
     global_key: str | None = None
     global_bpm: float | None = None
     notes: str | None = None