feat: implement AI-curated playlist service and dashboard integration

- Added hierarchical AGENTS.md knowledge base
- Implemented PlaylistService with 6h themed and 24h devotion mix logic
- Integrated AI theme generation for 6h playlists via Gemini/OpenAI
- Added /playlists/refresh and metadata endpoints to API
- Updated background worker with scheduled playlist curation
- Created frontend PlaylistsSection, Tooltip components and integrated into Dashboard
- Added Alembic migration for playlist tracking columns
- Fixed Docker healthcheck with curl installation

backend/app/main.py

@@ -1,3 +1,4 @@
+import os
 from fastapi import FastAPI, Depends, HTTPException, BackgroundTasks, Query
 from sqlalchemy.orm import Session, joinedload
 from datetime import datetime, timedelta
@@ -11,9 +12,15 @@ from .models import (
     AnalysisSnapshot,
 )
 from . import schemas
-from .ingest import ingest_recently_played
+from .ingest import (
+    ingest_recently_played,
+    get_spotify_client,
+    get_reccobeats_client,
+    get_genius_client,
+)
 from .services.stats_service import StatsService
 from .services.narrative_service import NarrativeService
+from .services.playlist_service import PlaylistService
 
 load_dotenv()
 
@@ -204,3 +211,107 @@ def get_sessions(
             "marathon_rate": session_stats.get("marathon_session_rate", 0),
         },
     }
+
+
+@app.post("/playlists/refresh/six-hour")
+async def refresh_six_hour_playlist(db: Session = Depends(get_db)):
+    """Triggers a 6-hour themed playlist refresh."""
+    try:
+        end_date = datetime.utcnow()
+        start_date = end_date - timedelta(hours=6)
+
+        playlist_service = PlaylistService(
+            db=db,
+            spotify_client=get_spotify_client(),
+            recco_client=get_reccobeats_client(),
+            narrative_service=NarrativeService(),
+        )
+
+        result = await playlist_service.curate_six_hour_playlist(start_date, end_date)
+
+        snapshot = AnalysisSnapshot(
+            date=datetime.utcnow(),
+            period_start=start_date,
+            period_end=end_date,
+            period_label="6h_refresh",
+            metrics_payload={},
+            narrative_report={},
+            playlist_theme=result.get("theme_name"),
+            playlist_theme_reasoning=result.get("description"),
+            six_hour_playlist_id=result.get("playlist_id"),
+        )
+        db.add(snapshot)
+        db.commit()
+
+        return result
+    except Exception as e:
+        print(f"Playlist Refresh Failed: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@app.post("/playlists/refresh/daily")
+async def refresh_daily_playlist(db: Session = Depends(get_db)):
+    """Triggers a 24-hour daily playlist refresh."""
+    try:
+        end_date = datetime.utcnow()
+        start_date = end_date - timedelta(days=1)
+
+        playlist_service = PlaylistService(
+            db=db,
+            spotify_client=get_spotify_client(),
+            recco_client=get_reccobeats_client(),
+            narrative_service=NarrativeService(),
+        )
+
+        result = await playlist_service.curate_daily_playlist(start_date, end_date)
+
+        snapshot = AnalysisSnapshot(
+            date=datetime.utcnow(),
+            period_start=start_date,
+            period_end=end_date,
+            period_label="24h_refresh",
+            metrics_payload={},
+            narrative_report={},
+            daily_playlist_id=result.get("playlist_id"),
+        )
+        db.add(snapshot)
+        db.commit()
+
+        return result
+    except Exception as e:
+        print(f"Daily Playlist Refresh Failed: {e}")
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@app.get("/playlists")
+async def get_playlists_metadata(db: Session = Depends(get_db)):
+    """Returns metadata for the managed playlists."""
+    latest_snapshot = (
+        db.query(AnalysisSnapshot)
+        .filter(AnalysisSnapshot.six_hour_playlist_id != None)
+        .order_by(AnalysisSnapshot.date.desc())
+        .first()
+    )
+
+    return {
+        "six_hour": {
+            "id": latest_snapshot.six_hour_playlist_id
+            if latest_snapshot
+            else os.getenv("SIX_HOUR_PLAYLIST_ID"),
+            "theme": latest_snapshot.playlist_theme if latest_snapshot else "N/A",
+            "reasoning": latest_snapshot.playlist_theme_reasoning
+            if latest_snapshot
+            else "N/A",
+            "last_refresh": latest_snapshot.date.isoformat()
+            if latest_snapshot
+            else None,
+        },
+        "daily": {
+            "id": latest_snapshot.daily_playlist_id
+            if latest_snapshot
+            else os.getenv("DAILY_PLAYLIST_ID"),
+            "last_refresh": latest_snapshot.date.isoformat()
+            if latest_snapshot
+            else None,
+        },
+    }