feat(dashboard): add plan data loading and lite task detail styling

- Add plan.json data loading to getSessionDetailData function for lite tasks
- Implement plan tab content styling with summary and approach sections
- Add plan metadata grid layout for displaying task planning information
- Create lite task detail page styles with task stats bar and status indicators
- Add context tab content styling with improved section hierarchy
- Implement path tags and JSON content display styles for plan details
- Add collapsible sections for organizing plan information
- Create comprehensive styling for context fields, modification points, and implementation steps
- Add array and nested object rendering styles for JSON data visualization
- Implement button styles for JSON view toggle functionality

ccw/src/core/server.js

@@ -214,6 +214,18 @@ async function getSessionDetailData(sessionPath, dataType) {
       }
     }
 
+    // Load plan.json (for lite tasks)
+    if (dataType === 'plan' || dataType === 'all') {
+      const planFile = join(normalizedPath, 'plan.json');
+      if (existsSync(planFile)) {
+        try {
+          result.plan = JSON.parse(readFileSync(planFile, 'utf8'));
+        } catch (e) {
+          result.plan = null;
+        }
+      }
+    }
+
     // Load IMPL_PLAN.md
     if (dataType === 'impl-plan' || dataType === 'all') {
       const implPlanFile = join(normalizedPath, 'IMPL_PLAN.md');