docs(18-04): complete global item catalog client plan

- SUMMARY.md with task commits and decisions
- STATE.md updated with progress and decisions
- ROADMAP.md updated with plan progress (4/5 plans complete)
- REQUIREMENTS.md: GLOB-03, GLOB-04, GLOB-05 marked complete

.planning/phases/18-global-items-public-profiles/18-04-SUMMARY.md

@@ -0,0 +1,104 @@
+---
+phase: 18-global-items-public-profiles
+plan: 04
+subsystem: ui
+tags: [react, tanstack-router, tanstack-query, tailwind, global-items]
+
+requires:
+  - phase: 18-02
+    provides: Global item API endpoints (search, detail, link/unlink)
+  - phase: 18-01
+    provides: globalItems and itemGlobalLinks schema tables
+provides:
+  - Global catalog browse/search page at /global-items
+  - Global item detail page with owner count at /global-items/:id
+  - GlobalItemCard component for catalog listings
+  - LinkToGlobalItem component for linking personal items to catalog
+  - useGlobalItems, useGlobalItem, useLinkItem, useUnlinkItem hooks
+affects: [18-05, public-profiles, collection-ui]
+
+tech-stack:
+  added: []
+  patterns: [debounced-search-input, global-item-query-keys]
+
+key-files:
+  created:
+    - src/client/hooks/useGlobalItems.ts
+    - src/client/components/GlobalItemCard.tsx
+    - src/client/components/LinkToGlobalItem.tsx
+    - src/client/routes/global-items/index.tsx
+    - src/client/routes/global-items/$globalItemId.tsx
+  modified: []
+
+key-decisions:
+  - "Debounce search at component level (300ms) rather than in hook"
+  - "LinkToGlobalItem as standalone component, not integrated into ItemForm yet"
+  - "Owner count badge in amber to differentiate from weight/price badges"
+
+patterns-established:
+  - "Global item query keys: ['global-items', query] for list, ['global-items', id] for detail"
+  - "Skeleton loading with static key array to avoid biome noArrayIndexKey rule"
+
+requirements-completed: [GLOB-03, GLOB-04, GLOB-05]
+
+duration: 4min
+completed: 2026-04-05
+---
+
+# Phase 18 Plan 04: Global Item Catalog Client Summary
+
+**Global catalog browse/search page, item detail with owner count, and link-to-catalog component using TanStack Router and Query**
+
+## Performance
+
+- **Duration:** 4 min
+- **Started:** 2026-04-05T11:14:25Z
+- **Completed:** 2026-04-05T11:18:40Z
+- **Tasks:** 3 (2 auto + 1 checkpoint auto-approved)
+- **Files created:** 5
+
+## Accomplishments
+- Global catalog browse page with debounced search, responsive grid, and skeleton loading states
+- Global item detail page showing brand, model, specs, image, description, and owner count badge
+- LinkToGlobalItem component with search dropdown for linking/unlinking personal items to catalog entries
+- Full set of TanStack Query hooks (useGlobalItems, useGlobalItem, useLinkItem, useUnlinkItem)
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Global item hooks and catalog pages** - `f53f66d` (feat)
+2. **Task 2: Link-to-global-item UI** - `f5233d0` (feat)
+3. **Task 3: Verify global catalog UI** - auto-approved checkpoint (no commit)
+
+## Files Created/Modified
+- `src/client/hooks/useGlobalItems.ts` - Query hooks for global items API (search, detail, link, unlink)
+- `src/client/components/GlobalItemCard.tsx` - Card component with brand, model, weight/price/category badges
+- `src/client/components/LinkToGlobalItem.tsx` - Search-based dropdown for linking personal items to catalog
+- `src/client/routes/global-items/index.tsx` - Catalog browse page with search and responsive grid
+- `src/client/routes/global-items/$globalItemId.tsx` - Detail page with owner count badge
+
+## Decisions Made
+- Debounce implemented at component level (useState + useEffect with 300ms timeout) rather than in the hook, keeping hooks simple
+- LinkToGlobalItem built as a standalone component that accepts itemId and linkedGlobalItemId props, making it easy to wire into any item view
+- Used amber color for owner count badge to visually differentiate from blue (weight) and green (price) badges
+- Skeleton loading uses static string array keys ("a" through "f") to satisfy biome's noArrayIndexKey lint rule
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+None.
+
+## User Setup Required
+None - no external service configuration required.
+
+## Next Phase Readiness
+- Client UI complete for global item browsing, searching, and linking
+- LinkToGlobalItem component ready to be wired into ItemForm or item detail views
+- Ready for Plan 18-05 (discovery feed and remaining UI integration)
+
+---
+*Phase: 18-global-items-public-profiles*
+*Completed: 2026-04-05*