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/models/table.py

@@ -0,0 +1,31 @@
+from sqlalchemy import Column, Integer, String, Boolean, Float, ForeignKey
+from sqlalchemy.orm import relationship
+from database import Base
+
+
+class TableGroup(Base):
+    __tablename__ = "table_groups"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String, nullable=False, unique=True)
+    prefix = Column(String, nullable=True)
+    sort_order = Column(Integer, default=0)
+    color = Column(String, nullable=True)
+
+    tables = relationship("Table", back_populates="group")
+    waiter_zones = relationship("WaiterZone", back_populates="group")
+
+
+class Table(Base):
+    __tablename__ = "tables"
+
+    id = Column(Integer, primary_key=True, index=True)
+    number = Column(Integer, nullable=False)
+    label = Column(String, nullable=True)
+    group_id = Column(Integer, ForeignKey("table_groups.id"), nullable=True)
+    is_active = Column(Boolean, default=True, nullable=False)
+    floor_x = Column(Float, nullable=True)
+    floor_y = Column(Float, nullable=True)
+
+    group = relationship("TableGroup", back_populates="tables")
+    orders = relationship("Order", back_populates="table")