refactor: extract FileBrowser and shared UI primitives (Task 1.2)

- Extract FileBrowser from inline definition in repo-workspace.tsx
- Create components/features/git/FileBrowser.tsx with module CSS
- Create reusable UI primitives: LoadingState, ErrorState, StatusBadge
- Create barrel exports for components/ui/ and components/features/git/
- Replace inline loading/error patterns in dashboard, sessions, repo-workspace

Quality gates: tsc (pass), eslint (pass)
Refs: repo-restructure Task 1.2

openspec/changes/repo-restructure/apply-1.2-report.md

@@ -0,0 +1,32 @@
+# Task 1.2 Apply Report: Extract FileBrowser and Shared UI Primitives
+
+**Status:** Success
+
+## Files Created (8)
+
+- `apps/web/src/components/features/git/FileBrowser.tsx` — Extracted FileBrowser component from inline definition in repo-workspace.tsx
+- `apps/web/src/components/features/git/FileBrowser.module.css` — CSS module for FileBrowser styles
+- `apps/web/src/components/ui/LoadingState.tsx` — Reusable loading component with customizable message
+- `apps/web/src/components/ui/ErrorState.tsx` — Reusable error component with optional retry button
+- `apps/web/src/components/ui/StatusBadge.tsx` — Reusable status badge component
+- `apps/web/src/components/ui/index.ts` — Barrel export for UI primitives
+- `apps/web/src/components/features/git/index.ts` — Barrel export for git feature components
+
+## Files Modified (3)
+
+- `apps/web/src/pages/repo-workspace.tsx` — Removed inline FileBrowser, imported from features/git, replaced loading/error with LoadingState/ErrorState
+- `apps/web/src/pages/dashboard.tsx` — Replaced inline loading/error with LoadingState/ErrorState
+- `apps/web/src/pages/sessions.tsx` — Replaced inline loading/error with LoadingState/ErrorState
+
+## Quality Gate Results
+
+- `npm run typecheck` (frontend): **PASS** — zero errors
+- `npm run lint` (frontend): **PASS** — zero warnings
+- `grep -n "const FileBrowser" pages/repo-workspace.tsx`: **PASS** — zero results (no inner component)
+- All 3 pages compile and import paths resolve correctly
+
+## Notes
+
+- FileBrowser CSS module created but global CSS classes remain in styles.css for backward compatibility during Phase 2
+- Icon import removed from repo-workspace.tsx since FileBrowser no longer uses it inline
+- All page loading/error patterns now use shared UI primitives