feat: add Integrations tab and responsive icon-only tabs

Move HA sources, weather sources, game integration, and MQTT settings
into a dedicated Integrations top-level tab with tab-registry pattern.
Collapse tab labels to icon-only at narrow desktop widths (<=1100px)
to prevent toolbar overflow.

server/src/wled_controller/templates/index.html

@@ -47,7 +47,8 @@
                 <button class="tab-btn" data-tab="automations" onclick="switchTab('automations')" role="tab" aria-selected="false" aria-controls="tab-automations" id="tab-btn-automations" title="Ctrl+2"><svg class="icon" viewBox="0 0 24 24"><rect width="8" height="4" x="8" y="2" rx="1" ry="1"/><path d="M16 4h2a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V6a2 2 0 0 1 2-2h2"/><path d="M12 11h4"/><path d="M12 16h4"/><path d="M8 11h.01"/><path d="M8 16h.01"/></svg> <span data-i18n="automations.title">Automations</span></button>
                 <button class="tab-btn" data-tab="targets" onclick="switchTab('targets')" role="tab" aria-selected="false" aria-controls="tab-targets" id="tab-btn-targets" title="Ctrl+3"><svg class="icon" viewBox="0 0 24 24"><path d="M4 14a1 1 0 0 1-.78-1.63l9.9-10.2a.5.5 0 0 1 .86.46l-1.92 6.02A1 1 0 0 0 13 10h7a1 1 0 0 1 .78 1.63l-9.9 10.2a.5.5 0 0 1-.86-.46l1.92-6.02A1 1 0 0 0 11 14z"/></svg> <span data-i18n="targets.title">Targets</span></button>
                 <button class="tab-btn" data-tab="streams" onclick="switchTab('streams')" role="tab" aria-selected="false" aria-controls="tab-streams" id="tab-btn-streams" title="Ctrl+4"><svg class="icon" viewBox="0 0 24 24"><path d="m17 2-5 5-5-5"/><rect width="20" height="15" x="2" y="7" rx="2"/></svg> <span data-i18n="streams.title">Sources</span></button>
-                <button class="tab-btn" data-tab="graph" onclick="switchTab('graph')" role="tab" aria-selected="false" aria-controls="tab-graph" id="tab-btn-graph" title="Ctrl+5"><svg class="icon" viewBox="0 0 24 24"><circle cx="5" cy="6" r="3"/><circle cx="19" cy="6" r="3"/><circle cx="12" cy="18" r="3"/><path d="M7.5 7.5 10.5 16"/><path d="M16.5 7.5 13.5 16"/></svg> <span data-i18n="graph.title">Graph</span></button>
+                <button class="tab-btn" data-tab="integrations" onclick="switchTab('integrations')" role="tab" aria-selected="false" aria-controls="tab-integrations" id="tab-btn-integrations" title="Ctrl+5"><svg class="icon" viewBox="0 0 24 24"><path d="M12 22v-5"/><path d="M15 8V2"/><path d="M17 8a1 1 0 0 1 1 1v4a4 4 0 0 1-4 4h-4a4 4 0 0 1-4-4V9a1 1 0 0 1 1-1z"/><path d="M9 8V2"/></svg> <span data-i18n="integrations.title">Integrations</span></button>
+                <button class="tab-btn" data-tab="graph" onclick="switchTab('graph')" role="tab" aria-selected="false" aria-controls="tab-graph" id="tab-btn-graph" title="Ctrl+6"><svg class="icon" viewBox="0 0 24 24"><circle cx="5" cy="6" r="3"/><circle cx="19" cy="6" r="3"/><circle cx="12" cy="18" r="3"/><path d="M7.5 7.5 10.5 16"/><path d="M16.5 7.5 13.5 16"/></svg> <span data-i18n="graph.title">Graph</span></button>
             </div>
             <div class="header-toolbar">
                 <a href="/docs" target="_blank" class="header-link" data-i18n-title="app.api_docs" title="API Docs">API</a>
@@ -145,6 +146,15 @@
                 </div>
             </div>
 
+            <div class="tab-panel" id="tab-integrations" role="tabpanel" aria-labelledby="tab-btn-integrations">
+                <div class="tree-layout">
+                    <nav class="tree-sidebar" id="integrations-tree-nav"></nav>
+                    <div class="tree-content" id="integrations-list">
+                        <div class="loading-spinner"></div>
+                    </div>
+                </div>
+            </div>
+
             <div class="tab-panel" id="tab-graph" role="tabpanel" aria-labelledby="tab-btn-graph">
                 <div id="graph-editor-content">
                     <div class="loading-spinner"></div>