Add priority queue to ai-service and STATUS.md workflow

- Introduce async priority queue service in ai-service; all /chat calls now route through it
- Refactor chat router to separate execute_chat (core logic) from the HTTP handler
- Add /queue endpoints (status, pause, resume, cancel) for queue management
- Update ai-service config to use Pydantic v2 model_config style
- Add STATUS.md files for backend, ai-service, doc-service, and frontend
- Document STATUS.md workflow in CLAUDE.md
- Update doc-service documents router and schemas; frontend DocumentsPage and API client

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

frontend/src/api/client.ts

@@ -98,6 +98,23 @@ export interface DocumentOut {
   categories: CategoryOut[];
 }
 
+export interface DocumentPage {
+  items: DocumentOut[];
+  total: number;
+  page: number;
+  pages: number;
+}
+
+export interface DocumentListParams {
+  page?: number;
+  per_page?: number;
+  sort?: string;
+  order?: "asc" | "desc";
+  status?: string;
+  document_type?: string;
+  search?: string;
+}
+
 export interface DocumentStatusOut {
   id: string;
   status: DocumentStatus;
@@ -106,8 +123,8 @@ export interface DocumentStatusOut {
   processed_at: string | null;
 }
 
-export const listDocuments = () =>
-  api.get<DocumentOut[]>("/documents").then((r) => r.data);
+export const listDocuments = (params: DocumentListParams = {}) =>
+  api.get<DocumentPage>("/documents", { params }).then((r) => r.data);
 
 export const getDocument = (id: string) =>
   api.get<DocumentOut>(`/documents/${id}`).then((r) => r.data);