Add routine management features for child and parent views

- Implemented routine child-mode flow tests to ensure proper functionality of routine assignment and task completion.
- Created notification tests for parent view to verify routine completion notifications for children.
- Developed ChildRoutineOverlay component for displaying routine tasks and handling user interactions.
- Added RoutineApproveDialog component for approving or rejecting completed routines.
- Created unit tests for ChildRoutineOverlay and RoutineEditView components to ensure correct behavior and rendering.
- Enhanced RoutineEditView with proper handling of task addition and form submission.

Co-authored-by: Copilot <copilot@github.com>

backend/tests/test_chore_confirmation.py

@@ -3,6 +3,7 @@ from tests.conftest import TEST_SECRET_KEY, TEST_REFRESH_TOKEN_EXPIRY_DAYS
 import os
 from werkzeug.security import generate_password_hash
 from datetime import date as date_type
+import api.child_api as child_api_module
 
 from flask import Flask
 from api.child_api import child_api
@@ -71,6 +72,24 @@ def setup_child_and_chore(child_name='TestChild', age=8, chore_points=10):
     return child['id'], 'chore1'
 
 
+def test_local_day_iso_check_handles_utc_rollover():
+    # 22:30 UTC on 2026-05-11 is 12:30 local on 2026-05-12 in Pacific/Kiritimati (UTC+14).
+    assert child_api_module._is_iso_timestamp_on_local_day(
+        '2026-05-11T22:30:00+00:00',
+        '2026-05-12',
+        'Pacific/Kiritimati',
+    )
+
+
+def test_local_day_epoch_check_handles_utc_rollover():
+    # Same instant as above represented as epoch seconds.
+    assert child_api_module._is_epoch_timestamp_on_local_day(
+        1778538600,
+        '2026-05-12',
+        'Pacific/Kiritimati',
+    )
+
+
 # ---------------------------------------------------------------------------
 # Child Confirm Flow
 # ---------------------------------------------------------------------------