feat: initial shared library extraction

Contains shared infrastructure for all coop services:
- shared/ (factory, urls, user_loader, context, internal_api, jinja_setup)
- models/ (User, Order, Calendar, Ticket, Product, Ghost CMS)
- db/ (SQLAlchemy async session, base)
- suma_browser/app/ (csrf, middleware, errors, authz, redis_cacher, payments, filters, utils)
- suma_browser/templates/ (shared base layouts, macros, error pages)
- static/ (CSS, JS, fonts, images)
- alembic/ (database migrations)
- config/ (app-config.yaml)
- editor/ (Lexical editor Node.js build)
- requirements.txt

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

models/order.py

@@ -0,0 +1,108 @@
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Optional, List
+
+from sqlalchemy import Integer, String, DateTime, ForeignKey, Numeric, func, Text
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from db.base import Base
+
+
+class Order(Base):
+    __tablename__ = "orders"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+
+    user_id: Mapped[Optional[int]] = mapped_column(ForeignKey("users.id"), nullable=True)
+    session_id: Mapped[Optional[str]] = mapped_column(String(64), index=True, nullable=True)
+
+    status: Mapped[str] = mapped_column(
+        String(32),
+        nullable=False,
+        default="pending",
+        server_default="pending",
+    )
+    currency: Mapped[str] = mapped_column(String(16), nullable=False, default="GBP")
+    total_amount: Mapped[float] = mapped_column(Numeric(12, 2), nullable=False)
+
+    # free-form description for the order
+    description: Mapped[Optional[str]] = mapped_column(Text, nullable=True, index=True)
+
+    # SumUp reference string (what we send as checkout_reference)
+    sumup_reference: Mapped[Optional[str]] = mapped_column(
+        String(255),
+        nullable=True,
+        index=True,
+    )
+
+    # SumUp integration fields
+    sumup_checkout_id: Mapped[Optional[str]] = mapped_column(
+        String(128),
+        nullable=True,
+        index=True,
+    )
+    sumup_status: Mapped[Optional[str]] = mapped_column(String(32), nullable=True)
+    sumup_hosted_url: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        nullable=False,
+        server_default=func.now(),
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        nullable=False,
+        server_default=func.now(),
+        onupdate=func.now(),
+    )
+
+    items: Mapped[List["OrderItem"]] = relationship(
+        "OrderItem",
+        back_populates="order",
+        cascade="all, delete-orphan",
+        lazy="selectin",
+    )
+    calendar_entries: Mapped[List["CalendarEntry"]] = relationship(
+        "CalendarEntry",
+        back_populates="order",
+        lazy="selectin",
+    )
+
+
+class OrderItem(Base):
+    __tablename__ = "order_items"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    order_id: Mapped[int] = mapped_column(
+        ForeignKey("orders.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+
+    product_id: Mapped[int] = mapped_column(
+        ForeignKey("products.id"),
+        nullable=False,
+    )
+    product_title: Mapped[Optional[str]] = mapped_column(String(512), nullable=True)
+
+    quantity: Mapped[int] = mapped_column(Integer, nullable=False, default=1)
+    unit_price: Mapped[float] = mapped_column(Numeric(12, 2), nullable=False)
+    currency: Mapped[str] = mapped_column(String(16), nullable=False, default="GBP")
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        nullable=False,
+        server_default=func.now(),
+    )
+
+    order: Mapped["Order"] = relationship(
+        "Order",
+        back_populates="items",
+    )
+
+    # NEW: link each order item to its product
+    product: Mapped["Product"] = relationship(
+        "Product",
+        back_populates="order_items",
+        lazy="selectin",
+    )