restore(mobile): restore mobile/ directory to pre-d2217531 state

Restored mobile/ from d22175310a711e7ebdd8062ae29a54f0136dc3f6^
(parent commit d94e9ca4bc).

Commit d22175310a (google-labs-jules[bot], 2026-03-23T14:45:22Z) introduced
an SSRF security fix for IMAP connections but unintentionally deleted or
truncated a large number of files across the repository, including 24 files
under mobile/.

This commit targets only the mobile/ directory and restores the following
files to their pre-d2217531 state:

- mobile/README.md
- mobile/app.json
- mobile/app/(tabs)/_layout.tsx
- mobile/app/(tabs)/file-detail.tsx  (re-added)
- mobile/app/+not-found.tsx          (re-added)
- mobile/app/_layout.tsx
- mobile/eslint.config.js            (re-added)
- mobile/package-lock.json
- mobile/package.json
- mobile/src/context/ShareContext.tsx
- mobile/src/i18n/de.json            (re-added)
- mobile/src/i18n/en.json            (re-added)
- mobile/src/i18n/es.json            (re-added)
- mobile/src/i18n/fr.json            (re-added)
- mobile/src/i18n/index.ts           (re-added)
- mobile/src/i18n/it.json            (re-added)
- mobile/src/screens/FileDetailScreen.tsx (re-added)
- mobile/src/screens/FilesScreen.tsx
- mobile/src/screens/LoginScreen.tsx
- mobile/src/screens/ProfileScreen.tsx
- mobile/src/screens/UploadScreen.tsx
- mobile/src/screens/WelcomeScreen.tsx
- mobile/src/services/api.ts
- mobile/src/utils/mimeTypes.ts      (re-added)
- mobile/src/utils/normalizeUri.ts   (re-added)

Security fixes introduced by d2217531 that are unrelated to mobile/
(IMAP SSRF fix in app/utils/network.py and app/tasks/imap_tasks.py)
are preserved — this restore targets only files under mobile/.

mobile/src/services/api.ts

@@ -26,6 +26,7 @@ export interface WhoAmIResponse {
   email: string | null;
   avatar_url: string | null;
   is_admin: boolean;
+  preferred_language: string | null;
 }
 
 export interface GenerateTokenResponse {
@@ -66,10 +67,42 @@ export interface FileRecord {
 }
 
 export interface UploadResponse {
-  task_id: string;
+  task_id?: string;
   status: string;
   original_filename: string;
   stored_filename: string;
+  duplicate_of?: {
+    duplicate_type: string;
+    original_file_id: number;
+    original_filename: string;
+    message: string;
+  };
+}
+
+export interface ProcessingLog {
+  id: number;
+  task_id: string;
+  step_name: string;
+  status: string;
+  message: string;
+  timestamp: string;
+}
+
+export interface FileDetail {
+  file: {
+    id: number;
+    filehash: string;
+    original_filename: string;
+    local_filename: string;
+    file_size: number;
+    mime_type: string;
+    created_at: string;
+  };
+  processing_status: ProcessingStatus;
+  logs: ProcessingLog[];
+  files_on_disk: {
+    original: boolean;
+  };
 }
 
 // ---------------------------------------------------------------------------
@@ -177,6 +210,11 @@ class DocuElevateAPI {
     return this.request<WhoAmIResponse>("GET", "/api/mobile/whoami");
   }
 
+  /** Sync the user's preferred UI language to the server. */
+  async setServerLanguage(lang: string): Promise<void> {
+    await this.request("POST", "/api/i18n/language", { body: { language: lang } });
+  }
+
   // -------------------------------------------------------------------------
   // Push notifications
   // -------------------------------------------------------------------------
@@ -223,6 +261,11 @@ class DocuElevateAPI {
     );
     return data.processing_status;
   }
+
+  /** Get full file details including processing logs. */
+  async getFileDetail(fileId: number): Promise<FileDetail> {
+    return this.request<FileDetail>("GET", `/api/files/${fileId}`);
+  }
 }
 
 export const api = new DocuElevateAPI();