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/models/chore_schedule.py

@@ -0,0 +1,71 @@
+from dataclasses import dataclass, field
+from typing import Literal
+from models.base import BaseModel
+
+
+@dataclass
+class DayConfig:
+    day: int      # 0=Sun, 1=Mon, ..., 6=Sat
+    hour: int     # 0–23 (24h)
+    minute: int   # 0, 15, 30, or 45
+
+    def to_dict(self) -> dict:
+        return {
+            'day': self.day,
+            'hour': self.hour,
+            'minute': self.minute,
+        }
+
+    @classmethod
+    def from_dict(cls, d: dict) -> 'DayConfig':
+        return cls(
+            day=d.get('day', 0),
+            hour=d.get('hour', 0),
+            minute=d.get('minute', 0),
+        )
+
+
+@dataclass
+class ChoreSchedule(BaseModel):
+    child_id: str
+    task_id: str
+    mode: Literal['days', 'interval']
+
+    # mode='days' fields
+    day_configs: list = field(default_factory=list)   # list of DayConfig dicts
+
+    # mode='interval' fields
+    interval_days: int = 2          # 2–7
+    anchor_weekday: int = 0         # 0=Sun–6=Sat
+    interval_hour: int = 0
+    interval_minute: int = 0
+
+    @classmethod
+    def from_dict(cls, d: dict) -> 'ChoreSchedule':
+        return cls(
+            child_id=d.get('child_id'),
+            task_id=d.get('task_id'),
+            mode=d.get('mode', 'days'),
+            day_configs=d.get('day_configs', []),
+            interval_days=d.get('interval_days', 2),
+            anchor_weekday=d.get('anchor_weekday', 0),
+            interval_hour=d.get('interval_hour', 0),
+            interval_minute=d.get('interval_minute', 0),
+            id=d.get('id'),
+            created_at=d.get('created_at'),
+            updated_at=d.get('updated_at'),
+        )
+
+    def to_dict(self) -> dict:
+        base = super().to_dict()
+        base.update({
+            'child_id': self.child_id,
+            'task_id': self.task_id,
+            'mode': self.mode,
+            'day_configs': self.day_configs,
+            'interval_days': self.interval_days,
+            'anchor_weekday': self.anchor_weekday,
+            'interval_hour': self.interval_hour,
+            'interval_minute': self.interval_minute,
+        })
+        return base