feat(search): add debounced search bar to bounties page (#823)

[wengkit218-pixel]

Summary

Adds a debounced search bar to the /bounties page that filters bounties client-side by title, description, skills, org name, and repo name — working alongside existing status and language filters.

Changes

BountyGrid.tsx

• New imports: useMemo, useEffect, useCallback, Search, X icons
• Search state: searchQuery (input) + debouncedQuery (300ms debounce via useEffect)
• Client-side filtering: useMemo over all loaded bounties, matching against title + description + skills + org_name + repo_name
• Search bar UI: Full-width input with Search icon, X clear button, placeholder text, styled with project tokens (bg-forge-800, border-border, focus:border-emerald)
• Empty state: Shows search-specific message (No bounties match "...") vs generic message
• Grid renders: Uses filteredBounties instead of allBounties
• Works with: Existing status dropdown + skill filter pills (all three filters compose together)

Acceptance Criteria

• Search bar visible on /bounties page
• Typing filters bounties in real-time (300ms debounce)
• Works alongside existing status and language filters
• Clear button resets search
• Empty state shows contextual message

Closes #823

[wengkit218-pixel]

💰 Wallet: 47HxQss7ctt6fFymSo8gevkYUWJPxieYFDG1eWQK7AjU

[wengkit218-pixel]

Closing - FNDRY tokens have no USD cash value. Submitted 2026-05-20, waited 27+ days with 0 reviews. Not a cash bounty.