feat(dashboard): unify icons with Lucide Icons library

- Introduce Lucide Icons via CDN for consistent SVG icons
- Replace emoji icons with Lucide SVG icons in sidebar navigation
- Fix Sessions/Explorer icon confusion (📁/📂 → history/folder-tree)
- Update top bar icons (logo, theme toggle, search, refresh)
- Update stats section icons with colored Lucide icons
- Add icon animations support (animate-spin for loading states)
- Update Explorer view with Lucide folder/file icons
- Support dark/light theme icon adaptation

Icon mapping:
- Explorer: folder-tree (was 📂)
- Sessions: history (was 📁)
- Overview: bar-chart-3
- Active: play-circle
- Archived: archive
- Lite Plan: file-edit
- Lite Fix: wrench
- MCP Servers: plug
- Hooks: webhook

ccw/src/templates/dashboard-js/components/navigation.js

@@ -96,6 +96,8 @@ function initNavigation() {
         renderMcpManager();
       } else if (currentView === 'project-overview') {
         renderProjectOverview();
+      } else if (currentView === 'explorer') {
+        renderExplorer();
       }
     });
   });
@@ -112,6 +114,8 @@ function updateContentTitle() {
     titleEl.textContent = 'Project Overview';
   } else if (currentView === 'mcp-manager') {
     titleEl.textContent = 'MCP Server Management';
+  } else if (currentView === 'explorer') {
+    titleEl.textContent = 'File Explorer';
   } else if (currentView === 'liteTasks') {
     const names = { 'lite-plan': 'Lite Plan Sessions', 'lite-fix': 'Lite Fix Sessions' };
     titleEl.textContent = names[currentLiteType] || 'Lite Tasks';