Add vibe-aware playlists with CLAP text embeddings

Blend taste profile with text-embedded mood descriptions (e.g. "chill
ambient lo-fi") using pre-blended vector search against the existing
HNSW index. New optional `vibe` and `alpha` params on playlist generate
and recommendations endpoints. Backward compatible — no vibe = pure
taste profile (alpha=1.0).

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

README.md

@@ -51,7 +51,7 @@ docker exec haunt-fm alembic upgrade head
 | POST | `/api/history/webhook` | Log a listen event (from HA automation) |
 | POST | `/api/admin/discover` | Expand listening history via Last.fm |
 | POST | `/api/admin/build-taste-profile` | Rebuild taste profile from embeddings |
-| GET | `/api/recommendations?limit=50` | Get ranked recommendations |
+| GET | `/api/recommendations?limit=50&vibe=chill+ambient` | Get ranked recommendations (optional vibe) |
 | POST | `/api/playlists/generate` | Generate and optionally play a playlist |
 
 ## Usage
@@ -69,11 +69,26 @@ curl -X POST http://192.168.86.51:8321/api/playlists/generate \
   }'
 ```
 
+### Generate a vibe-based playlist
+
+```bash
+curl -X POST http://192.168.86.51:8321/api/playlists/generate \
+  -H "Content-Type: application/json" \
+  -d '{
+    "total_tracks": 15,
+    "vibe": "chill ambient lo-fi",
+    "speaker_entity": "media_player.living_room_speaker_2",
+    "auto_play": true
+  }'
+```
+
 **Parameters:**
 - `total_tracks` — number of tracks in the playlist (default 20)
 - `known_pct` — percentage of known-liked tracks vs new discoveries (default 30)
 - `speaker_entity` — Music Assistant entity ID (must be a `_2` suffix entity)
 - `auto_play` — `true` to immediately play on the speaker
+- `vibe` — text description of the desired mood/vibe (e.g. "chill lo-fi beats", "upbeat party music"). Uses CLAP text embeddings to match tracks in the same vector space as audio.
+- `alpha` — blend factor between taste profile and vibe (default 0.5). `1.0` = pure taste profile, `0.0` = pure vibe match, `0.5` = equal blend. Ignored when no vibe is provided.
 
 ### Speaker entities
 
@@ -113,6 +128,9 @@ curl -X POST http://192.168.86.51:8321/api/admin/build-taste-profile
 
 # Get recommendations (without playing)
 curl http://192.168.86.51:8321/api/recommendations?limit=20
+
+# Get vibe-matched recommendations
+curl "http://192.168.86.51:8321/api/recommendations?limit=20&vibe=dark+electronic&alpha=0.3"
 ```
 
 ## Pipeline Stages