Redesign doc service UX for scale + add group-based document sharing

- Three-column layout: Sidebar + SourcePanel (views + searchable category tree) + main
- DocumentSlideOver (480px right panel): inline editing, type picker, AI suggestion confirm/reject,
  categories combobox, tags editor, sharing section, raw text, re-analyse/delete actions
- ManageCategoriesDialog: inline rename, delete with confirm, search filter
- DocumentsPage rewrite: filter chip system, multi-file upload queue, drag-and-drop overlay,
  bulk actions bar (share/delete), smart TanStack Query polling, URL-driven view state
- Sidebar simplified: per-category NavLinks removed; Documents = single NavLink under Apps
- Backend: document_shares table (migration 0004), share CRUD endpoints, shared-with-me view,
  N+1-safe share_count via GROUP BY, recipient download access, X-User-Groups header enforcement
- Gateway proxy: injects X-User-Groups header into all document + category proxy requests
- Backend users: GET /api/users/me/groups endpoint for share picker combobox
- CLAUDE.md, STATUS.md files, and changelog updated

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

frontend/src/api/client.ts

@@ -111,6 +111,20 @@ export interface DocumentOut {
   watch_path: string | null;
   suggested_folder: string | null;
   suggested_filename: string | null;
+  share_count: number;
+}
+
+export interface SharedDocumentOut extends DocumentOut {
+  shared_by_user_id: string;
+  shared_via_group_id: string;
+}
+
+export interface DocumentShareOut {
+  id: string;
+  document_id: string;
+  group_id: string;
+  shared_by_user_id: string;
+  created_at: string;
 }
 
 export interface DocumentPage {
@@ -142,6 +156,18 @@ export interface DocumentStatusOut {
 export const listDocuments = (params: DocumentListParams = {}) =>
   api.get<DocumentPage>("/documents", { params }).then((r) => r.data);
 
+export const listSharedWithMe = (params: DocumentListParams = {}) =>
+  api.get<DocumentPage>("/documents/shared-with-me", { params }).then((r) => r.data);
+
+export const getDocumentShares = (docId: string) =>
+  api.get<DocumentShareOut[]>(`/documents/${docId}/shares`).then((r) => r.data);
+
+export const addDocumentShare = (docId: string, groupId: string) =>
+  api.post<DocumentShareOut>(`/documents/${docId}/shares`, { group_id: groupId }).then((r) => r.data);
+
+export const removeDocumentShare = (docId: string, groupId: string) =>
+  api.delete(`/documents/${docId}/shares/${groupId}`);
+
 export const getDocument = (id: string) =>
   api.get<DocumentOut>(`/documents/${id}`).then((r) => r.data);
 
@@ -289,6 +315,16 @@ export const updateDocumentLimits = (max_pdf_mb: number) =>
 export const getDocumentLimits = () =>
   api.get<Record<string, unknown>>("/settings/documents/limits").then((r) => r.data);
 
+// --- User groups (current user's own memberships) ---
+export interface UserGroupOut {
+  id: string;
+  name: string;
+  description: string | null;
+}
+
+export const getMyGroups = () =>
+  api.get<UserGroupOut[]>("/users/me/groups").then((r) => r.data);
+
 // --- Groups (admin only) ---
 export interface GroupOut {
   id: string;