This PR breaks the large web and player bootstrap files into smaller modules with clearer ownership.

Web changes:

Split shared helpers, bootstrap logic, route groups, and upload-sync behavior out of web.js.
Kept web.js focused on wiring and server startup.
Fixed screen playlist reassignment so changing a screen’s playlist now triggers a refresh.
Fixed single-slide playlist refresh behavior so updates do not get stuck behind the current slide.
Player changes:

Split websocket/runtime handling into runtime.js.
Split playlist assembly and revision hashing into playlist.js.
Split onboarding and player HTTP routes into dedicated modules.
Split render utilities and template loading into render-helpers.js.
Kept player.js mostly as startup/orchestration.
Validation:

Rebuilt both services with Docker Compose.
Smoke-checked web and player routes after the refactor.
Verified get_errors was clean on the touched modules.

docker-compose.yml

@@ -39,6 +39,7 @@ services:
     environment:
       NODE_ENV: ${NODE_ENV:-production}
       PLAYER_PORT: ${PLAYER_PORT:-3001}
+      PLAYER_PUBLIC_BASE_URL: ${PLAYER_PUBLIC_BASE_URL:-http://localhost:3001}
       DB_HOST: ${DB_HOST:-mysql}
       DB_PORT: ${DB_PORT:-3306}
       DB_NAME: ${DB_NAME:-signage}