feat: add Turso (libSQL) storage support for EdgeOne deployment

- Add TursoAdapter implementing DatabaseAdapter interface using @libsql/client
- Add 'turso' storage type to db.ts storage selector (reuses D1Storage)
- Add init-turso.js script for database migration and admin initialization
- Add @libsql/client dependency to package.json
- Update next.config.js to exclude @libsql/client from client-side bundle
- Update edgeone-deploy.yml workflow with TURSO_URL and TURSO_TOKEN secrets
- Update edgeone-build.mjs runtime env keys to include Turso variables
- Update .env.edgeone.example with Turso deployment instructions
- Update README.md with Turso as recommended storage for EdgeOne

Turso provides free SQLite-compatible cloud database (libSQL) with:
- 500 databases, 9GB storage, 1B row reads/month on free tier
- HTTP API compatible with edge/serverless environments
- Full SQLite syntax compatibility, reuses existing migrations

package.json

@@ -22,6 +22,7 @@
     "watch-room:server": "node server/watch-room-standalone-server.js --port 3001 --auth YOUR_SECRET_KEY",
     "init:sqlite": "node scripts/init-sqlite.js",
     "init:postgres": "node scripts/init-postgres.js",
+    "init:turso": "node scripts/init-turso.js",
     "db:reset": "rm -f .data/moontv.db .data/moontv.db-shm .data/moontv.db-wal && node scripts/init-sqlite.js",
     "build:edgeone": "pnpm edgeone:build",
     "preview:edgeone": "BUILD_TARGET=edgeone EDGEONE_PAGES=1 node scripts/edgeone-local-preview.mjs",
@@ -61,6 +62,7 @@
     "he": "^1.2.0",
     "hls.js": "^1.6.10",
     "https-proxy-agent": "^7.0.6",
+    "@libsql/client": "^0.15.0",
     "lucide-react": "^0.438.0",
     "media-icons": "^1.1.5",
     "mux.js": "^6.3.0",