fix(web): widget cache-busting, dead frontend code, and dependency pins (#656)

- Plugin-supplied widgets load as /static/plugin-widgets/...js?v=<plugin
  version>, so an update isn't hidden behind the year-long immutable cache.
- Fire-and-forget loadInstalledPlugins() calls catch the rejection it has
  already reported, so the global handler no longer adds a second toast.
- Timezone picker renders again when the General partial is re-injected.
- Remove dead code: executePluginAction's six plugin-id fallbacks and
  [DEBUG] logging, window.currentPluginConfig and every read of it, the
  file-upload JSON delete branch, unused PluginAPI / PluginInstallManager /
  PluginStateManager helpers, loadPluginWidgetsFromManifest, the stale
  install_manager.js and LEDVisibility fallbacks, error_handler.js's global
  escapeHtml, 13 unused CSS rules, and stale comments/no-op returns.
- pytz < 2027, psutil < 7 in requirements-test.txt, pytest-cov < 8.
- Pin anthropics/claude-code-action to the commit v1 resolves to.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

web_interface/templates/v3/base.html

@@ -275,17 +275,17 @@
     <!-- Alpine.js app function - defined early so it's available when Alpine initializes -->
     <script src="{{ url_for('static', filename='v3/js/app-early.js') }}"></script>
 
+    <!-- App shell (full app(), Alpine stores, SSE streams). Deferred so it
+         doesn't block rendering, and placed before Alpine: deferred scripts run
+         in document order, and its alpine:init listener must be registered
+         before Alpine starts. -->
+    <script defer src="{{ url_for('static', filename='v3/js/app-shell.js') }}"></script>
     <!-- Alpine.js for reactive components.
          Load the local copy first (always works, no CDN round-trip, no AP-mode
          branch needed). `defer` on an HTML-parsed <script> is honored and runs
          after DOM parse but before DOMContentLoaded, which is exactly what
          Alpine wants — so no deferLoadingAlpine gymnastics are needed.
          The inline rescue below only fires if the local file is missing. -->
-    <!-- App shell (full app(), Alpine stores, SSE streams). Deferred so it
-         doesn't block rendering, and placed before Alpine: deferred scripts run
-         in document order, and its alpine:init listener must be registered
-         before Alpine starts. -->
-    <script defer src="{{ url_for('static', filename='v3/js/app-shell.js') }}"></script>
     <script defer src="{{ url_for('static', filename='v3/js/alpinejs.min.js') }}"></script>
     <script>
         // Rescue: if the local Alpine didn't load for any reason, pull the CDN

web_interface/templates/v3/partials/display.html

@@ -1044,11 +1044,7 @@ document.getElementById('brightness').addEventListener('input', function() {
     }
     function startSyncPolling() {
         updateSyncUI();
-        if (window.LEDVisibility) {
-            window.LEDVisibility.onActive('display', startSyncTimer, stopSyncTimer, 'display-sync-status');
-        } else if (!window.syncStatusInterval) {
-            window.syncStatusInterval = setInterval(pollSyncStatus, 5000);
-        }
+        window.LEDVisibility.onActive('display', startSyncTimer, stopSyncTimer, 'display-sync-status');
     }
 
     if (document.readyState === 'loading') {

web_interface/templates/v3/partials/general.html

@@ -88,9 +88,6 @@
         </div>
         <script>
         (function() {
-            // Track if already initialized to prevent re-render
-            if (window.__timezoneWidgetInitialized) return;
-
             function initTimezoneWidget() {
                 if (!window.LEDMatrixWidgets) { setTimeout(initTimezoneWidget, 50); return; }
                 var widget = window.LEDMatrixWidgets.get('timezone-selector');
@@ -107,7 +104,6 @@
                     fieldId: 'timezone',
                     name: 'timezone'
                 });
-                window.__timezoneWidgetInitialized = true;
             }
             if (document.readyState === 'loading') {
                 document.addEventListener('DOMContentLoaded', initTimezoneWidget);

web_interface/templates/v3/partials/logs.html

@@ -264,11 +264,7 @@ window._filteredLogs = [];
         }
         stopRealtimeLogs();
     }
-    if (window.LEDVisibility) {
-        window.LEDVisibility.onActive('logs', startLogsActivity, stopLogsActivity);
-    } else {
-        startLogsActivity();
-    }
+    window.LEDVisibility.onActive('logs', startLogsActivity, stopLogsActivity);
 
     // Handle window resize for responsive height. Added once: this script
     // re-runs on every partial load, and the handler reads window globals.

web_interface/templates/v3/partials/plugin_config.html

@@ -1101,6 +1101,7 @@
                 (function() {
                     var WIDGET = {{ str_widget|tojson|safe }};
                     var PLUGIN = {{ plugin_id|tojson|safe }};
+                    var VERSION = {{ ((plugin.version if plugin is defined and plugin else '') or '')|string|tojson|safe }};
                     function initPluginWidget() {
                         if (!window.LEDMatrixWidgets || !window.LEDMatrixWidgets.ensureWidget) {
                             setTimeout(initPluginWidget, 50);
@@ -1109,7 +1110,7 @@
                         var container = document.getElementById('{{ field_id }}_container');
                         var fallback = document.getElementById('{{ field_id }}');
                         if (!container) { return; }
-                        window.LEDMatrixWidgets.ensureWidget(WIDGET, PLUGIN).then(function(available) {
+                        window.LEDMatrixWidgets.ensureWidget(WIDGET, PLUGIN, VERSION).then(function(available) {
                             if (!available) { container.remove(); return; }
                             var widget = window.LEDMatrixWidgets.get(WIDGET);
                             if (!widget || typeof widget.render !== 'function') { container.remove(); return; }