fix(mobile): iOS share sheet, empty files tab, and stuck upload status

- app.json: add CFBundleDocumentTypes to iOS infoPlist so the app
  appears in the iOS Share Sheet; add ACTION_SEND/SEND_MULTIPLE
  intentFilters for Android share intent support

- src/context/ShareContext.tsx (new): React context that queues files
  received from the share sheet and delivers them to UploadScreen

- app/_layout.tsx: wrap in ShareProvider; add Linking handler
  (makeUrlHandler factory + getInitialURL cold-start + addEventListener
  warm-start) to capture file:// and content:// URLs

- src/services/api.ts: fix FileRecord interface (original_filename,
  nested ProcessingStatus, mime_type); fix UploadResponse interface;
  fix listFiles() (per_page param, unwrap data.files); add
  getFileStatus(fileId) for single-file status polling

- src/screens/FilesScreen.tsx: use file.original_filename and
  file.processing_status.status; fix statusEmoji to use actual backend
  status values (completed/pending/duplicate)

- src/screens/UploadScreen.tsx: consume ShareContext for auto-upload of
  shared files; add 5-second polling loop (search by filename → file_id
  → getFileStatus) to show real-time server processing status;
  uploadFile wrapped in useCallback; proper effect dependency arrays

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

mobile/src/services/api.ts

@@ -41,21 +41,27 @@ export interface DeviceRegistration {
   platform: "ios" | "android" | "web";
 }
 
+export interface ProcessingStatus {
+  status: string;
+  last_step: string | null;
+  has_errors: boolean;
+  total_steps: number;
+}
+
 export interface FileRecord {
   id: number;
-  filename: string;
-  status: string;
-  created_at: string;
+  original_filename: string;
   file_size: number | null;
-  content_type: string | null;
-  owner_id: string | null;
+  mime_type: string | null;
+  created_at: string;
+  processing_status: ProcessingStatus;
 }
 
 export interface UploadResponse {
   task_id: string;
   status: string;
-  message: string;
-  filename: string;
+  original_filename: string;
+  stored_filename: string;
 }
 
 // ---------------------------------------------------------------------------
@@ -186,12 +192,21 @@ class DocuElevateAPI {
     return this.request<UploadResponse>("POST", "/api/ui-upload", { formData });
   }
 
-  /** List recently processed files. */
-  async listFiles(page = 1, pageSize = 20): Promise<FileRecord[]> {
-    return this.request<FileRecord[]>(
+  /** List recently processed files, optionally filtered by filename search. */
+  async listFiles(page = 1, pageSize = 20, search?: string): Promise<FileRecord[]> {
+    let url = `/api/files?page=${page}&per_page=${pageSize}`;
+    if (search) url += `&search=${encodeURIComponent(search)}`;
+    const data = await this.request<{ files: FileRecord[]; pagination: unknown }>("GET", url);
+    return data.files;
+  }
+
+  /** Get the processing status for a single file by its ID. */
+  async getFileStatus(fileId: number): Promise<ProcessingStatus> {
+    const data = await this.request<{ processing_status: ProcessingStatus }>(
       "GET",
-      `/api/files?page=${page}&page_size=${pageSize}`
+      `/api/files/${fileId}`
     );
+    return data.processing_status;
   }
 }