UI Phase 2 (L0): shared layout primitives + chrome standardization

Extract four shared layout widgets from the best existing implementations and
adopt them across list/overview screens, deleting duplicated inline code.
Layout/consistency only — no behavior change.

New primitives (lib/widgets/):
- app_section_header.dart  — AppSectionHeader (azure accent bar + uppercase
  telemetry label; promoted from the dashboard's _sectionTitle).
- app_metric_card.dart     — AppMetricCard (uppercase label + mono value on a
  flat hairline surface; unifies KPI/stat tiles).
- app_status_summary.dart  — AppStatusSummaryRow/Item/Chip (dot + count + label,
  selectable; semantic AppStatusColors).
- app_filter_bar.dart      — AppFilterBar (responsive filter-row chrome).

Adopted / de-duplicated:
- Dashboard: _MetricCard now wraps AppMetricCard; section titles use
  AppSectionHeader (removed local _sectionTitle).
- Tickets / Tasks / ISR: three separate summary-chip implementations
  (_StatusSummaryCard x2, _SummaryChip) collapsed into AppStatusSummaryRow.
- Network Map overview: Sites/Devices tiles -> AppMetricCard (removed local
  _SummaryCard).
- Workforce: "Duty Schedules" header -> AppSectionHeader with trailing chip.

Verified: flutter analyze lib clean; flutter build web green; visual QA (tickets
+ ISR summary chips) in dark.

Co-Authored-By: claude-flow <ruv@ruv.net>

lib/screens/it_service_requests/it_service_requests_list_screen.dart

@@ -18,6 +18,7 @@ import '../../theme/m3_motion.dart';
 import '../../utils/app_time.dart';
 import '../../utils/snackbar.dart';
 import '../../theme/app_status_colors.dart';
+import '../../widgets/app_status_summary.dart';
 import '../../widgets/m3_card.dart';
 import '../../widgets/mono_text.dart';
 import '../../widgets/reconnect_overlay.dart';
@@ -535,8 +536,6 @@ class _StatusSummaryRow extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final cs = Theme.of(context).colorScheme;
-    final status = AppStatusColors.of(context);
     final pending = requests
         .where((r) => r.status == ItServiceRequestStatus.pendingApproval)
         .length;
@@ -554,88 +553,38 @@ class _StatusSummaryRow extends StatelessWidget {
         .where((r) => r.status == ItServiceRequestStatus.completed)
         .length;
 
-    return SingleChildScrollView(
-      scrollDirection: Axis.horizontal,
-      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
-      child: Row(
-        children: [
-          _SummaryChip(
-            label: 'Pending',
-            count: pending,
-            color: status.warning.color,
-            selected: selectedStatus == ItServiceRequestStatus.pendingApproval,
-            onTap: () => onStatusTap(ItServiceRequestStatus.pendingApproval),
-          ),
-          const SizedBox(width: 8),
-          _SummaryChip(
-            label: 'Scheduled',
-            count: scheduled,
-            color: status.info.color,
-            selected: selectedStatus == ItServiceRequestStatus.scheduled,
-            onTap: () => onStatusTap(ItServiceRequestStatus.scheduled),
-          ),
-          const SizedBox(width: 8),
-          _SummaryChip(
-            label: 'In Progress',
-            count: inProgress,
-            color: cs.secondary,
-            selected: selectedStatus == ItServiceRequestStatus.inProgress,
-            onTap: () => onStatusTap(ItServiceRequestStatus.inProgress),
-          ),
-          const SizedBox(width: 8),
-          _SummaryChip(
-            label: 'Completed',
-            count: completed,
-            color: status.success.color,
-            selected: selectedStatus == ItServiceRequestStatus.completed,
-            onTap: () => onStatusTap(ItServiceRequestStatus.completed),
-          ),
-        ],
-      ),
-    );
-  }
-}
-
-class _SummaryChip extends StatelessWidget {
-  const _SummaryChip({
-    required this.label,
-    required this.count,
-    required this.color,
-    required this.selected,
-    required this.onTap,
-  });
-
-  final String label;
-  final int count;
-  final Color color;
-  final bool selected;
-  final VoidCallback onTap;
-
-  @override
-  Widget build(BuildContext context) {
-    return M3Card.filled(
-      onTap: onTap,
-      color: selected
-          ? color.withValues(alpha: 0.2)
-          : Theme.of(context).colorScheme.surfaceContainerHighest,
-      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
-      child: Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
-        child: Row(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            Text(
-              count.toString(),
-              style: Theme.of(context).textTheme.titleMedium?.copyWith(
-                fontWeight: FontWeight.bold,
-                color: color,
-              ),
-            ),
-            const SizedBox(width: 8),
-            Text(label, style: Theme.of(context).textTheme.bodySmall),
-          ],
+    return AppStatusSummaryRow(
+      padding: const EdgeInsets.symmetric(vertical: 8),
+      items: [
+        AppStatusSummaryItem(
+          label: 'Pending',
+          count: pending,
+          kind: StatusKind.warning,
+          selected: selectedStatus == ItServiceRequestStatus.pendingApproval,
+          onTap: () => onStatusTap(ItServiceRequestStatus.pendingApproval),
         ),
-      ),
+        AppStatusSummaryItem(
+          label: 'Scheduled',
+          count: scheduled,
+          kind: StatusKind.neutral,
+          selected: selectedStatus == ItServiceRequestStatus.scheduled,
+          onTap: () => onStatusTap(ItServiceRequestStatus.scheduled),
+        ),
+        AppStatusSummaryItem(
+          label: 'In Progress',
+          count: inProgress,
+          kind: StatusKind.info,
+          selected: selectedStatus == ItServiceRequestStatus.inProgress,
+          onTap: () => onStatusTap(ItServiceRequestStatus.inProgress),
+        ),
+        AppStatusSummaryItem(
+          label: 'Completed',
+          count: completed,
+          kind: StatusKind.success,
+          selected: selectedStatus == ItServiceRequestStatus.completed,
+          onTap: () => onStatusTap(ItServiceRequestStatus.completed),
+        ),
+      ],
     );
   }
 }