feat(notifications): day sheet notification types

Add daySheetId field to NotificationItem model (Brick-managed), extract
notificationTitle/notificationIcon to top-level testable functions, add
five day-sheet notification cases, and wire tap/banner routing for
day-sheet detail and approvals tab.
Co-Authored-By: claude-flow <ruv@ruv.net>

lib/brick/adapters/notification_item_adapter.g.dart

@@ -23,6 +23,9 @@ Future<NotificationItem> _$NotificationItemFromSupabase(
         ? null
         : data['announcement_id'] as String?,
     messageId: data['message_id'] == null ? null : data['message_id'] as int?,
+    daySheetId: data['day_sheet_id'] == null
+        ? null
+        : data['day_sheet_id'] as String?,
     type: data['type'] as String,
     createdAt: DateTime.parse(data['created_at'] as String),
     readAt: data['read_at'] == null
@@ -49,6 +52,7 @@ Future<Map<String, dynamic>> _$NotificationItemToSupabase(
     'it_service_request_id': instance.itServiceRequestId,
     'announcement_id': instance.announcementId,
     'message_id': instance.messageId,
+    'day_sheet_id': instance.daySheetId,
     'type': instance.type,
     'created_at': instance.createdAt.toIso8601String(),
     'read_at': instance.readAt?.toIso8601String(),
@@ -77,6 +81,9 @@ Future<NotificationItem> _$NotificationItemFromSqlite(
         ? null
         : data['announcement_id'] as String?,
     messageId: data['message_id'] == null ? null : data['message_id'] as int?,
+    daySheetId: data['day_sheet_id'] == null
+        ? null
+        : data['day_sheet_id'] as String?,
     type: data['type'] as String,
     createdAt: DateTime.parse(data['created_at'] as String),
     readAt: data['read_at'] == null
@@ -103,6 +110,7 @@ Future<Map<String, dynamic>> _$NotificationItemToSqlite(
     'it_service_request_id': instance.itServiceRequestId,
     'announcement_id': instance.announcementId,
     'message_id': instance.messageId,
+    'day_sheet_id': instance.daySheetId,
     'type': instance.type,
     'created_at': instance.createdAt.toIso8601String(),
     'read_at': instance.readAt?.toIso8601String(),
@@ -160,6 +168,10 @@ class NotificationItemAdapter
       association: false,
       columnName: 'message_id',
     ),
+    'daySheetId': const RuntimeSupabaseColumnDefinition(
+      association: false,
+      columnName: 'day_sheet_id',
+    ),
     'type': const RuntimeSupabaseColumnDefinition(
       association: false,
       columnName: 'type',
@@ -245,6 +257,12 @@ class NotificationItemAdapter
       iterable: false,
       type: int,
     ),
+    'daySheetId': const RuntimeSqliteColumnDefinition(
+      association: false,
+      columnName: 'day_sheet_id',
+      iterable: false,
+      type: String,
+    ),
     'type': const RuntimeSqliteColumnDefinition(
       association: false,
       columnName: 'type',