feat(programmer): day sheets + approvals tabs

- day_sheet_snapshot_builder.dart: buildSnapshotForSheet (approved →
  stored snapshot, else live buildDayRows), groupSheetsByDate (descending
  keys), approvalCounts (pending/awaiting/approved)
- approvals_tab.dart: status filter chips, programmer dropdown,
  ReportDateFilter.controlled, date-grouped cards with Auto/Early/Round
  badges, checkbox multi-select, bulk Approve selected (n) flow
- day_sheets_tab.dart: Today card (live rows, total, status, Submit day),
  Needs your attention (disapproved), history with AppStatusSummaryRow
  All/Pending/Disapproved/Approved filter
- programmerTasksTabsFor: admin → [monitor, approvals, mine, all];
  programmer → [mine, all, daySheets]
- programmer_tasks_list_screen.dart: wire approvals + daySheets cases

Tests: 15 passing (day_sheet_tabs_test + programmer_tabs_test)

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

test/programmer_tabs_test.dart

@@ -49,18 +49,26 @@ void main() {
   setUpAll(AppTime.initialize);
 
   group('programmerTasksTabsFor', () {
-    test('tabs in this slice', () {
+    test('admin gets monitor + approvals + mine + all', () {
       expect(
         programmerTasksTabsFor(isStrictAdmin: true),
         [
           ProgrammerTasksTab.monitor,
+          ProgrammerTasksTab.approvals,
           ProgrammerTasksTab.mine,
           ProgrammerTasksTab.all,
         ],
       );
+    });
+
+    test('programmer gets mine + all + daySheets', () {
       expect(
         programmerTasksTabsFor(isStrictAdmin: false),
-        [ProgrammerTasksTab.mine, ProgrammerTasksTab.all],
+        [
+          ProgrammerTasksTab.mine,
+          ProgrammerTasksTab.all,
+          ProgrammerTasksTab.daySheets,
+        ],
       );
     });
   });