refactor: rename project Lyria Studio → Kithara Studio

- App name, UI text, page titles → Kithara Studio
- Python module: lyria_client.py → kithara_client.py
- Tailwind color classes: lyria-* → kithara-*
- CSS custom properties: --lyria-* → --kithara-*
- Database: lyria.db → kithara.db
- Package name: kithara-studio-frontend
- localStorage key: kithara-saved-searches
- Add project logo (lyre icon, black on transparent, invert via CSS)

Preserved as Google's property:
- LYRIA_API_KEY, LYRIA_BASE_URL, LYRIA_DEFAULT_MODEL env vars
- LYRIA_MODELS dict and model IDs (lyria-3-clip-preview, lyria-3-pro-preview)
- Google Lyria API references in error messages and docstrings

README.md

@@ -1,4 +1,4 @@
-# Lyria Studio
+# Kithara Studio
 
 A webapp for generating, playing, and storing music clips using Google's Lyria music generation models.
 
@@ -23,7 +23,7 @@ npm run dev
 
 ## Architecture
 
-- **Backend**: FastAPI (Python) — async Lyria API client, SQLite metadata, file storage
+- **Backend**: FastAPI (Python) — async API client for Google's Lyria models, SQLite metadata, file storage
 - **Frontend**: React + Vite + TypeScript + Tailwind — dark theme, audio player
 - **Storage**: SQLite for clip metadata, local filesystem for MP3 files
 
@@ -40,9 +40,9 @@ npm run dev
 
 ## Models
 
-- **v0.1**: Lyria 3 Clip Preview (30s, REST)
-- **v0.2**: Lyria 3 Pro (structure-aware, ~3min)
-- **v0.3**: Lyria RealTime (WebSocket streaming)
+- **v0.1**: Google Lyria 3 Clip Preview (30s, REST)
+- **v0.2**: Google Lyria 3 Pro (structure-aware, ~3min)
+- **v0.3**: Google Lyria RealTime (WebSocket streaming)
 
 ## License