feat(licserver): add partner API proxy routes and types

- New: lib/types/licserver.ts (PartnerDto, paged result, problem)
- New: app/api/licserver/partners/route.ts (GET search/list)
- New: app/api/licserver/partners/[id]/route.ts (GET by UUID)
- Updated: .env.example with LICSERVER_BASE_URL + LICSERVER_API_KEY

Auth-guarded via Supabase session. API key is server-side only.
Upstream: http://192.168.178.174:9980 (internal container network)

shop/.env.example

@@ -2,3 +2,7 @@
 # https://app.supabase.com/project/_/settings/api
 NEXT_PUBLIC_SUPABASE_URL=your-project-url
 NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY=your-publishable-or-anon-key
+
+# CASPOS LicServer (internal container network — server-side only, never expose to browser)
+LICSERVER_BASE_URL=http://192.168.178.174:9980
+LICSERVER_API_KEY=your-licserver-api-key