Implement critical sidebar handling improvements in huntarr-dev.mdc

- Addressed the issue of multiple sidebars displaying simultaneously, causing navigation confusion.
- Updated the flash prevention script in new-main.js to ensure only the relevant sidebar is shown based on the current section.
- Added detailed implementation requirements and testing instructions to ensure proper functionality across devices.

Author: Admin9705

.cursor/rules/huntarr-dev.mdc

@@ -348,6 +348,45 @@ echo "13. Synology optimization bypass violations: $(grep -r "sqlite3.connect\|P
 - **Debug Logging**: Always add comprehensive console.log statements to track initialization flow
 - **Testing**: Refresh page, navigate to section, check browser console for proper initialization sequence
 
+### Sidebar Implementation Pattern (Critical)
+- **Problem**: Multiple sidebars showing simultaneously causing visual clutter and navigation confusion
+- **Root Cause**: Flash prevention script in `new-main.js` showing main sidebar on page load before specialized sidebar logic runs
+- **Pattern**: Flash prevention checks localStorage but doesn't account for specialized sidebars (Requestarr, Settings)
+- **Symptom**: Both main sidebar and specialized sidebar visible at same time, especially on mobile
+- **Critical Fix**: Update flash prevention to hide main sidebar when specialized sidebar should be active
+- **Solution Pattern**:
+  ```javascript
+  // In flash prevention script (around line 90-120 in new-main.js)
+  // Check if we should show a specialized sidebar instead of main sidebar
+  const currentSection = localStorage.getItem('huntarrCurrentSection') || 'home';
+  const requestarrSections = ['requestarr-home', 'requestarr-history'];
+  const settingsSections = ['settings', 'scheduling'];
+  
+  if (requestarrSections.includes(currentSection)) {
+      // Show Requestarr sidebar, hide main sidebar
+      document.getElementById('sidebar').style.display = 'none';
+      document.getElementById('requestarrSidebar').style.display = 'block';
+  } else if (settingsSections.includes(currentSection)) {
+      // Show Settings sidebar, hide main sidebar  
+      document.getElementById('sidebar').style.display = 'none';
+      document.getElementById('settingsSidebar').style.display = 'block';
+  } else {
+      // Show main sidebar, hide specialized sidebars
+      document.getElementById('sidebar').style.display = 'block';
+      document.getElementById('requestarrSidebar').style.display = 'none';
+      document.getElementById('settingsSidebar').style.display = 'none';
+  }
+  ```
+- **Files Affected**: `/frontend/static/js/new-main.js` (flash prevention script)
+- **Implementation Requirements**:
+  1. Always check localStorage section before showing any sidebar
+  2. Hide all other sidebars when showing one specific sidebar
+  3. Use consistent section naming: `requestarr-home`, `requestarr-history`, `settings`, `scheduling`
+  4. Test on both desktop and mobile to ensure no double sidebars
+  5. Ensure return buttons properly switch back to main sidebar
+- **Mobile Compatibility**: Flash prevention must work on mobile where sidebar space is limited
+- **Testing**: Navigate between sections, refresh page, check that only one sidebar shows at a time
+
 ## 🎯 DEBUGGING APPROACH
 
 ### Systematic Issue Discovery