feat(oauth): import favoris/abos Google (YouTube) et Twitch vers abonnements/likes

- Backend: server/oauth.mjs (auth URL, echange code, refresh, fetch
  subscriptions/likes Google, follows Twitch), table oauth_connections
  + migration, routes /api/oauth/:provider/{url,callback,preview,import},
  /api/oauth/{status,connections}
- Front: /library/import (connect, preview, import), service
  oauth-import, lien depuis Abonnements
- Config: GOOGLE_CLIENT_ID/SECRET/REDIRECT_URI, TWITCH_REDIRECT_URI,
  OAUTH_APP_BASE_URL documentes (.env.example, docker-compose),
  passthrough docker-compose.local.yml, roadmap README cochee

docker-compose/docker-compose.local.yml

@@ -25,6 +25,12 @@ services:
       - VIMEO_ACCESS_TOKEN=${VIMEO_ACCESS_TOKEN}
       - TWITCH_CLIENT_ID=${TWITCH_CLIENT_ID}
       - TWITCH_CLIENT_SECRET=${TWITCH_CLIENT_SECRET}
+      - TWITCH_REDIRECT_URI=${TWITCH_REDIRECT_URI}
+      - GOOGLE_CLIENT_ID=${GOOGLE_CLIENT_ID}
+      - GOOGLE_CLIENT_SECRET=${GOOGLE_CLIENT_SECRET}
+      - GOOGLE_REDIRECT_URI=${GOOGLE_REDIRECT_URI}
+      - OAUTH_APP_BASE_URL=${OAUTH_APP_BASE_URL:-http://localhost:4200}
+      - HOST_PORT=${HOST_PORT:-4200}
       - DOWNLOAD_PROVIDERS=${DOWNLOAD_PROVIDERS:-youtube,dailymotion,twitch,peertube,odysee,rumble}
       - DOWNLOAD_MAX_CONCURRENT=${DOWNLOAD_MAX_CONCURRENT:-2}
       # --- YouTube hybride (Steps 17-18) : innertube > scrape yt-dlp > API ---