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/documents/document_card.dart

@@ -6,33 +6,45 @@ import '../../models/document_model.dart';
 class DocumentCard extends StatelessWidget {
   final DocumentModel doc;
   final Future<void> Function(DocumentModel) onPrint;
+  final bool isUnsynced;
 
   const DocumentCard({
     super.key,
     required this.doc,
     required this.onPrint,
+    this.isUnsynced = false,
   });
 
   @override
   Widget build(BuildContext context) {
-    final isProductScan = doc.orderUntuk == 'PRODUCT SCAN';
+    final isProductScan = doc.docType == 'Product';
     
     // Header category text
     final categoryText = isProductScan
         ? (doc.items.isNotEmpty ? doc.items.first.namaBarang : 'Product Scan')
         : (doc.namaPenerima.isNotEmpty ? doc.namaPenerima : 'Staff Toko');
     
-    // Category color (greenish-blue for product, orange-yellow for DO)
-    final categoryColor = isProductScan ? AppConfig.primaryColor : Colors.orange.shade700;
+    // Category color: Product → green (primaryColor), DO → orange (doModeColor).
+    // doModeColor is the shared constant for the DO orange cue across the app
+    // (camera drawer, tab switcher, and here) — was an ad-hoc inline value.
+    final categoryColor = isProductScan ? AppConfig.primaryColor : AppConfig.doModeColor;
+
+    // Sync status badge (see docs/api-contract-map.md G6 - a document can be
+    // corrected locally after its PUT sync failed; the corrected copy is
+    // shown here, so the badge must reflect that it hasn't reached the
+    // server yet rather than always claiming "Terkonfirmasi").
+    final badgeLabel = isUnsynced ? 'Belum Tersinkron' : 'Terkonfirmasi';
+    final badgeColor = isUnsynced ? Colors.deepOrange : AppConfig.successColor;
 
     // Bold title
     final boldTitle = isProductScan 
         ? doc.noDo 
         : doc.noPo;
 
-    // Subtitle text
+    // Subtitle text. Product Scan no longer links to a PO document (field
+    // removed - user request), so its subtitle is just the expiry date.
     final subtitleText = isProductScan
-        ? '${_formatDateString(doc.alamat.replaceAll("Product Scan: Expired ", ""))} • ${doc.noPo}'
+        ? _formatDateString(doc.alamat.replaceAll("Product Scan: Expired ", ""))
         : '${doc.tanggal} • ${doc.items.length} Item';
 
     return Card(
@@ -92,17 +104,17 @@ class DocumentCard extends StatelessWidget {
               Column(
                 crossAxisAlignment: CrossAxisAlignment.end,
                 children: [
-                  // Status badge (e.g. Approved / Terkonfirmasi)
+                  // Status badge (Terkonfirmasi / Belum Tersinkron)
                   Container(
                     padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                     decoration: BoxDecoration(
-                      color: AppConfig.successColor.withOpacity(0.1),
+                      color: badgeColor.withOpacity(0.1),
                       borderRadius: BorderRadius.circular(AppConfig.borderRadiusSmall),
                     ),
                     child: Text(
-                      'Terkonfirmasi',
+                      badgeLabel,
                       style: AppConfig.bodySmall.copyWith(
-                        color: AppConfig.successColor,
+                        color: badgeColor,
                         fontWeight: FontWeight.bold,
                         fontSize: 11,
                       ),