feat: quick-find search for clients and pets (GH #97, GRO-140)

Backend:
- GET /api/search?q={query} — returns up to 10 matching active clients and 10
  matching pets in a single request; clients matched on name/email/phone,
  pets matched on name/breed with owner name included
- Special chars (%, _, \) escaped before ILIKE to prevent injection/accidents
- Disabled clients excluded; pets from disabled client owners excluded via JOIN filter
- Route registered under protected API (auth + RBAC middleware applies automatically)
- Export `ilike` from @groombook/db alongside existing drizzle-orm helpers

Frontend:
- GlobalSearch component in sticky admin header: debounced input (300ms),
  grouped dropdown (Clients / Pets sections), loading/empty states
- Client results show name + phone; pet results show name, breed, owner name
- Touch-friendly: 44px input height, 48px min row height, full-width dropdown
- Outside-click closes dropdown; selecting a result navigates to /admin/clients

Tests (apps/api/src/__tests__/search.test.ts):
- 400 on missing/empty/whitespace q
- Returns matching clients and pets
- Empty arrays on no match
- Response shape always has clients/pets keys
- Special character inputs handled without errors

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/App.tsx

@@ -13,6 +13,7 @@ import { CustomerPortal } from "./portal/CustomerPortal.js";
 import { DevLoginSelector, getDevUser } from "./pages/DevLoginSelector.js";
 import { DevSessionIndicator } from "./components/DevSessionIndicator.js";
 import { BrandingProvider, useBranding } from "./BrandingContext.js";
+import { GlobalSearch } from "./components/GlobalSearch.js";
 
 const NAV_LINKS = [
   { to: "/admin", label: "Appointments" },
@@ -68,6 +69,7 @@ function AdminLayout() {
             {branding.businessName}
           </strong>
         </div>
+        <GlobalSearch />
         <Link
           to="/admin/book"
           style={{