feat: complete LOW priority code quality improvements

Backend:
- LOW-002: Add Query validation with max page size limits (100)
- LOW-003: Replace magic strings with TaskStatus.is_done flag
- LOW-004: Add 'creation' trigger type validation
- Add action_executor.py with UpdateFieldAction and AutoAssignAction

Frontend:
- LOW-005: Replace TypeScript 'any' with 'unknown' + type guards
- LOW-006: Add ConfirmModal component with A11Y support
- LOW-007: Add ToastContext for user feedback notifications
- LOW-009: Add Skeleton components (17 loading states replaced)
- LOW-010: Setup Vitest with 21 tests for ConfirmModal and Skeleton

Components updated:
- App.tsx, ProtectedRoute.tsx, Spaces.tsx, Projects.tsx, Tasks.tsx
- ProjectSettings.tsx, AuditPage.tsx, WorkloadPage.tsx, ProjectHealthPage.tsx
- Comments.tsx, AttachmentList.tsx, TriggerList.tsx, TaskDetailModal.tsx
- NotificationBell.tsx, BlockerDialog.tsx, CalendarView.tsx, WorkloadUserDetail.tsx

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/tests/test_triggers.py

@@ -375,3 +375,119 @@ class TestTriggerAPI:
 
         assert response.status_code == 400
         assert "Invalid operator" in response.json()["detail"]
+
+
+class TestTriggerActionRollback:
+    """Tests for trigger action rollback mechanism."""
+
+    def test_multi_action_rollback_on_failure(self, db, test_task, test_project, test_user, test_status):
+        """Test that when one action fails, all previous actions are rolled back.
+
+        Scenario:
+        1. Create a trigger with 2 actions: update_field (priority) + update_field (invalid status_id)
+        2. The first action should update priority to 'high'
+        3. The second action should fail because of invalid status_id
+        4. The first action's change should be rolled back
+        """
+        # Record original priority
+        original_priority = test_task.priority
+
+        # Create a trigger with multiple actions where the second one will fail
+        trigger = Trigger(
+            id=str(uuid.uuid4()),
+            project_id=test_project.id,
+            name="Multi-Action Trigger",
+            description="Test rollback on failure",
+            trigger_type="field_change",
+            conditions={
+                "field": "status_id",
+                "operator": "changed_to",
+                "value": test_status[1].id,
+            },
+            actions=[
+                # First action: update priority (should succeed)
+                {
+                    "type": "update_field",
+                    "field": "priority",
+                    "value": "high",
+                },
+                # Second action: update to invalid status (should fail)
+                {
+                    "type": "update_field",
+                    "field": "status_id",
+                    "value": "non-existent-status-id",
+                },
+            ],
+            is_active=True,
+            created_by=test_user.id,
+        )
+        db.add(trigger)
+        db.commit()
+
+        old_values = {"status_id": test_status[0].id}
+        new_values = {"status_id": test_status[1].id}
+
+        # Execute trigger - second action should fail
+        logs = TriggerService.evaluate_triggers(db, test_task, old_values, new_values, test_user)
+        db.commit()
+
+        # Verify trigger execution failed
+        assert len(logs) == 1
+        assert logs[0].status == "failed"
+        assert logs[0].error_message is not None
+        assert "not found" in logs[0].error_message.lower()
+
+        # Refresh task from database to get the actual state
+        db.refresh(test_task)
+
+        # Verify that the first action's change was rolled back
+        # Priority should remain unchanged (not 'high')
+        assert test_task.priority == original_priority, (
+            f"Expected priority to be rolled back to '{original_priority}', "
+            f"but got '{test_task.priority}'"
+        )
+
+    def test_all_actions_succeed_committed(self, db, test_task, test_project, test_user, test_status):
+        """Test that when all actions succeed, changes are committed."""
+        # Create a trigger with multiple successful actions
+        trigger = Trigger(
+            id=str(uuid.uuid4()),
+            project_id=test_project.id,
+            name="Success Trigger",
+            description="Test successful commit",
+            trigger_type="field_change",
+            conditions={
+                "field": "status_id",
+                "operator": "changed_to",
+                "value": test_status[1].id,
+            },
+            actions=[
+                # First action: update priority
+                {
+                    "type": "update_field",
+                    "field": "priority",
+                    "value": "urgent",
+                },
+            ],
+            is_active=True,
+            created_by=test_user.id,
+        )
+        db.add(trigger)
+        db.commit()
+
+        old_values = {"status_id": test_status[0].id}
+        new_values = {"status_id": test_status[1].id}
+
+        # Execute trigger
+        logs = TriggerService.evaluate_triggers(db, test_task, old_values, new_values, test_user)
+        db.commit()
+
+        # Verify trigger execution succeeded
+        assert len(logs) == 1
+        assert logs[0].status == "success"
+
+        # Refresh task from database
+        db.refresh(test_task)
+
+        # Verify that the change was committed
+        assert test_task.priority == "urgent"