feat: initial commit — local services (backend + manager dashboard + waiter PWA)

Includes all work to date:
- local_backend: FastAPI backend with products, orders, tables, shifts, cloud sync
- manager_dashboard: React manager UI with product/category management, reports, settings
- waiter_pwa: React PWA for waiter devices
- Category reparent endpoint and UI
- Waiter domain: local_ip sent on heartbeat, waiter_domain persisted from cloud response
- QR code modal in AppInfoTab for waiter domain
- Product form: number input spinners removed, category pre-selected on new product
- Category row: count badge moved to far right

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

local_backend/schemas/shift.py

@@ -0,0 +1,38 @@
+from pydantic import BaseModel
+from typing import Optional, List
+from schemas.base import UTCDatetime
+
+
+class ShiftBreakOut(BaseModel):
+    id: int
+    shift_id: int
+    started_at: UTCDatetime
+    ended_at: Optional[UTCDatetime] = None
+
+    model_config = {"from_attributes": True}
+
+
+class WaiterShiftOut(BaseModel):
+    id: int
+    waiter_id: int
+    waiter_name: Optional[str] = None
+    business_day_id: int
+    started_at: UTCDatetime
+    ended_at: Optional[UTCDatetime] = None
+    starting_cash: Optional[float] = None
+    total_collected: Optional[float] = None
+    net_to_deliver: Optional[float] = None
+    is_active: bool = True
+    notes: Optional[str] = None
+    breaks: List[ShiftBreakOut] = []
+
+    model_config = {"from_attributes": True}
+
+
+class StartShiftRequest(BaseModel):
+    starting_cash: Optional[float] = None
+    waiter_id: Optional[int] = None  # manager use: start shift for a specific waiter
+
+
+class EndShiftRequest(BaseModel):
+    notes: Optional[str] = None