feat: add lookup functionality for IP/domain verification and enhance dashboard links

Introduced a new lookup feature allowing users to quickly verify IP addresses or domains against community lists. Updated the DashboardQuickLinks component to include a new action for IP/domain checks, enhancing user navigation. Expanded API documentation to include the new lookup endpoint and its response structure, ensuring comprehensive coverage of the feature. Updated UI design documentation to reflect the integration of the lookup functionality.

docs/api.md

@@ -33,6 +33,15 @@
 - `POST /v1/modules`, `PATCH /v1/modules/{module_id}`, `DELETE /v1/modules/{module_id}`
 - `GET|POST|PATCH|DELETE` для `.../cdn-sources`, `.../as-entries`, `.../domain-entries`, `.../ip-range-entries`
 - `POST /v1/modules/{module_id}/refresh`
+- `GET /v1/router-lists/catalog` — агрегированный каталог модулей/entries/communities
+
+### Lookup
+
+- `GET /v1/lookup?q=` — быстрая проверка IP или FQDN в списках (viewer+).
+  - Слой `entry`: `IP_RANGES` (`CIDR.Contains`) / `DOMAINS` (нормализованный FQDN).
+  - Слой `snapshot`: материализованные `module_prefix_snapshot` (для IP — Contains по всем модулям; для домена — `source=domain` у matched DOMAINS-модулей).
+  - В каждом матче — community (`community_id` / значение / title).
+  - Live DoH не выполняется. Контракт: OpenAPI `lookupMembership`.
 
 ### DoH profiles