Add TimeSelector and ScheduleModal components with tests

- Implemented TimeSelector component for selecting time with AM/PM toggle and minute/hour increment/decrement functionality.
- Created ScheduleModal component for scheduling chores with options for specific days or intervals.
- Added utility functions for scheduling logic in scheduleUtils.ts.
- Developed comprehensive tests for TimeSelector and scheduleUtils functions to ensure correct behavior.

backend/db/task_extensions.py

@@ -0,0 +1,27 @@
+from db.db import task_extensions_db
+from models.task_extension import TaskExtension
+from tinydb import Query
+
+
+def get_extension(child_id: str, task_id: str, date: str) -> TaskExtension | None:
+    q = Query()
+    result = task_extensions_db.search(
+        (q.child_id == child_id) & (q.task_id == task_id) & (q.date == date)
+    )
+    if not result:
+        return None
+    return TaskExtension.from_dict(result[0])
+
+
+def add_extension(extension: TaskExtension) -> None:
+    task_extensions_db.insert(extension.to_dict())
+
+
+def delete_extensions_for_child(child_id: str) -> None:
+    q = Query()
+    task_extensions_db.remove(q.child_id == child_id)
+
+
+def delete_extensions_for_task(task_id: str) -> None:
+    q = Query()
+    task_extensions_db.remove(q.task_id == task_id)