fix: resolve search dropdown unable to reopen in same session

[Dhavanesh24cs412]

Description

Fixes issue #650 where the framework and library dropdown menus in the search modal could only be opened once per search session.

What Changed

• Removed modal={true} prop from Dropdown component that was blocking re-opens
• Replaced defensive event handlers with intelligent onInteractOutside handler
• Added DOM boundary detection to distinguish between inside/outside clicks
• Dropdown state is properly managed via SearchFiltersContext

Closes #650

Testing

• [x] Dropdown opens on first click
• [x] Dropdown closes on second click
• [x] Dropdown opens again on third click (previously broken - NOW FIXED!)
• [x] Multiple open/close cycles work consistently
• [x] Keyboard navigation works correctly (arrow keys, escape key)
• [x] Clicking outside dropdown closes it naturally
• [x] Framework preference persists correctly
• [x] No console errors or warnings
• [x] Tested locally on localhost:3000

Technical Details

Root Cause

The modal={true} prop in Radix Dropdown creates a modal context that blocks interactions with elements outside the dropdown, preventing proper state management for reopening.

Solution

Implemented an intelligent onInteractOutside handler that:

• Allows natural closing when clicking outside the dropdown
• Prevents closing when clicking on dropdown UI elements
• Uses DOM selectors ([role="listbox"] and button[class*="dropdown"]) to intelligently determine boundaries

Files Changed

• src/components/Dropdown.tsx: Added onInteractOutside with boundary detection
• src/components/SearchModal.tsx: Removed modal={true} prop

Why This Matters

TanStack Docs search is a critical feature. Users often need to filter by multiple libraries/frameworks in a single search session, making this dropdown reopening capability essential for a smooth user experience.