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>

lib/screens/programmer_tasks/programmer_tasks_tabs.dart

@@ -7,16 +7,24 @@
 /// approvals and daySheets are deferred to later slices.
 enum ProgrammerTasksTab { monitor, approvals, mine, all, daySheets }
 
-/// Returns the ordered tab list for the current role in this slice.
+/// Returns the ordered tab list for the current role.
+///
+/// Admin:      [monitor, approvals, mine, all]
+/// Programmer: [mine, all, daySheets]
 List<ProgrammerTasksTab> programmerTasksTabsFor({required bool isStrictAdmin}) {
   if (isStrictAdmin) {
     return [
       ProgrammerTasksTab.monitor,
+      ProgrammerTasksTab.approvals,
       ProgrammerTasksTab.mine,
       ProgrammerTasksTab.all,
     ];
   }
-  return [ProgrammerTasksTab.mine, ProgrammerTasksTab.all];
+  return [
+    ProgrammerTasksTab.mine,
+    ProgrammerTasksTab.all,
+    ProgrammerTasksTab.daySheets,
+  ];
 }
 
 /// Parses a URL query-parameter value to a [ProgrammerTasksTab].