feat: add Bugs & Fixes category to documentation

Added new "Bugs" group to release notes system for documenting
bug fixes and troubleshooting guides.

Changes:
- Added "Bugs & Fixes" group to _index.json (order: 4)
- Added "webpack-module-resolution" category under bugs group
- Created comprehensive MDX documentation for webpack fix
- Updated TypeScript types to include 'bugs' as valid group
- Updated sort order in getAllReleases() function
- Updated getReleasesGrouped() to include bugs filter
- Updated sidebar to expand bugs group by default

Content:
- Detailed webpack module resolution bug documentation
- Root cause analysis with technical explanation
- Solution implementation with code examples
- Prevention best practices
- Quick reference troubleshooting table
- Related issues and future improvements

Structure:
Group: Bugs & Fixes (order: 4)
└── Webpack Module Resolution (order: 10)
    - Error: Cannot read properties of undefined (reading 'call')
    - Fix: Wrapper component pattern
    - Status: Completed
    - Version: 0.2.1

This creates a dedicated space for documenting production issues,
their solutions, and lessons learned for future reference.

app/(marketing)/releases/components/release-sidebar.tsx

@@ -27,6 +27,7 @@ export function ReleaseSidebar({ releases, metadata }: ReleaseSidebarProps) {
     foundation: true,
     features: true,
     infrastructure: true,
+    bugs: true,
   })
 
   const toggleGroup = (groupId: string) => {