feat(app): scan-mode sync, confirmation-gated documents, single-pass product classification

Fixes reported from APK field testing: DO/Product scan mode was inconsistent
between the camera drawer and documents screen (now one shared provider,
with an orange/green color cue); unconfirmed scans leaked into history with
placeholder data before the user tapped confirm (backend now gates
GET /documents on a new `confirmed` column, flipped only by PUT); and
Product Scan ran the GPU classifier twice, once at upload and again on
review (now a single pass at upload, persisted and read directly by the
editor). Also removes the unused "Hubungkan ke PO" field and fabricated
PO/SO/DO placeholder values from the Product Scan flow, closes out the
per-document-polling and save-recovery tasks (6.1/6.3), and splits several
touched files to stay under the repo's 256-line guideline.

Full detail in docs/iteration-log.md and backend/docs/iteration-log.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

lib/features/auth/auth_provider.dart

@@ -2,6 +2,8 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import '../../core/network/api_client.dart';
 import '../../config/app_config.dart';
+import '../../main.dart';
+import '../documents/pending_documents_provider.dart';
 
 class AuthNotifier extends StateNotifier<bool> {
   AuthNotifier(this._ref) : super(false);
@@ -57,6 +59,11 @@ class AuthNotifier extends StateNotifier<bool> {
         throw Exception("Token otentikasi tidak ditemukan dalam respon");
       }
       
+      // Clear any pre-existing local data before saving the new token/profile
+      final localStorage = _ref.read(localStorageProvider);
+      await localStorage.clearAll();
+      _ref.read(pendingDocumentsProvider.notifier).clearQueue();
+      
       final prefs = await SharedPreferences.getInstance();
       await prefs.setString('auth_token', token);
       if (profile != null) {
@@ -76,6 +83,13 @@ class AuthNotifier extends StateNotifier<bool> {
     await prefs.remove('auth_token');
     await prefs.remove('nama_toko');
     await prefs.remove('kode_toko');
+    
+    final localStorage = _ref.read(localStorageProvider);
+    await localStorage.clearAll();
+    
+    // Clear pending documents queue in memory
+    _ref.read(pendingDocumentsProvider.notifier).clearQueue();
+    
     state = false;
   }
 }