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.

src/web/public/js/theme-init.js

@@ -1,20 +1,16 @@
 (function () {
-  var storageKey = 'web-theme';
-  var theme = 'light';
+  var storageKey = 'lte-theme';
+  var theme = 'auto';
 
   try {
     var storedTheme = window.localStorage.getItem(storageKey);
-    if (storedTheme === 'dark' || storedTheme === 'light') {
+    if (storedTheme === 'dark' || storedTheme === 'light' || storedTheme === 'auto') {
       theme = storedTheme;
-    } else if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
-      theme = 'dark';
     }
   } catch (error) {
-    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
-      theme = 'dark';
-    }
+    theme = 'auto';
   }
 
-  document.documentElement.dataset.theme = theme;
+  document.documentElement.dataset.bsTheme = theme;
   document.documentElement.style.colorScheme = theme;
 }());