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/camera/camera_drawer_mode_toggle.dart

@@ -0,0 +1,125 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../../config/app_config.dart';
+import 'scan_mode_provider.dart';
+
+/// DO / Product Scan mode toggle pill rendered in the [CameraDrawer].
+///
+/// Extracted from [CameraDrawer] to keep that file under the 256-line §3
+/// threshold (AGENTS.md §3, touched during task 8.1). Reads and writes
+/// [scanModeProvider] directly — the global source of truth shared with
+/// [DocumentsScreen] (task 8.1, docs/api-contract-map.md G11).
+///
+/// Color convention:
+///   - DO active      → [AppConfig.doModeColor] (orange)
+///   - Product active → [AppConfig.primaryColor] (green)
+class CameraDrawerModeToggle extends ConsumerWidget {
+  const CameraDrawerModeToggle({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final activeMode = ref.watch(scanModeProvider);
+
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 24.0),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Text(
+            'Mode',
+            style: AppConfig.bodySmall.copyWith(
+              color: Colors.grey.shade500,
+              fontWeight: FontWeight.w600,
+              letterSpacing: 0.5,
+            ),
+          ),
+          const SizedBox(height: 8),
+          Container(
+            height: 48,
+            decoration: BoxDecoration(
+              color: Colors.grey.shade100,
+              borderRadius: BorderRadius.circular(12),
+            ),
+            child: Padding(
+              padding: const EdgeInsets.all(4.0),
+              child: Row(
+                children: [
+                  _buildSegment(
+                    ref: ref,
+                    value: 'DO',
+                    label: 'DO Scan',
+                    activeIcon: Icons.description,
+                    inactiveIcon: Icons.description_outlined,
+                    activeMode: activeMode,
+                    activeColor: AppConfig.doModeColor,
+                  ),
+                  _buildSegment(
+                    ref: ref,
+                    value: 'Product',
+                    label: 'Product Scan',
+                    activeIcon: Icons.inventory_2,
+                    inactiveIcon: Icons.inventory_2_outlined,
+                    activeMode: activeMode,
+                    activeColor: AppConfig.primaryColor,
+                  ),
+                ],
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildSegment({
+    required WidgetRef ref,
+    required String value,
+    required String label,
+    required IconData activeIcon,
+    required IconData inactiveIcon,
+    required String activeMode,
+    required Color activeColor,
+  }) {
+    final isActive = activeMode == value;
+    return Expanded(
+      child: GestureDetector(
+        behavior: HitTestBehavior.opaque,
+        onTap: () => ref.read(scanModeProvider.notifier).state = value,
+        child: Container(
+          decoration: BoxDecoration(
+            color: isActive ? activeColor : Colors.transparent,
+            borderRadius: BorderRadius.circular(8),
+            boxShadow: isActive
+                ? [
+                    BoxShadow(
+                      color: activeColor.withOpacity(0.2),
+                      blurRadius: 4,
+                      offset: const Offset(0, 2),
+                    )
+                  ]
+                : [],
+          ),
+          alignment: Alignment.center,
+          child: Row(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              Icon(
+                isActive ? activeIcon : inactiveIcon,
+                size: 16,
+                color: isActive ? Colors.white : Colors.grey.shade500,
+              ),
+              const SizedBox(width: 6),
+              Text(
+                label,
+                style: AppConfig.bodyMedium.copyWith(
+                  fontWeight: isActive ? FontWeight.bold : FontWeight.normal,
+                  color: isActive ? Colors.white : Colors.grey.shade600,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}