Replace 21 Jinja render_template() calls with sx render functions

Phase 1: Wire 16 events routes to existing sx render functions
- slot, slots, ticket_types, ticket_type, calendar_entries,
  calendar_entry, calendar_entry/admin

Phase 2: Orders checkout return (2 calls)
- New orders/sx/checkout.sx with return page components
- New render_checkout_return_page() in orders/sx/sx_components.py

Phase 3: Blog menu items (3 calls)
- New blog/sx/menu_items.sx with search result components
- New render_menu_item_form() and render_page_search_results()
  in blog/sx/sx_components.py

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

orders/sx/sx_components.py

@@ -394,3 +394,82 @@ async def render_checkout_error_page(ctx: dict, error: str | None = None, order:
     filt = _checkout_error_filter_sx()
     content = _checkout_error_content_sx(error, order)
     return full_page_sx(ctx, header_rows=hdr, filter=filt, content=content)
+
+
+# ---------------------------------------------------------------------------
+# Public API: Checkout return
+# ---------------------------------------------------------------------------
+
+def _ticket_items_sx(order_tickets: list | None) -> str:
+    """Render ticket items for an order as sx."""
+    if not order_tickets:
+        return ""
+    items = []
+    for tk in order_tickets:
+        st = tk.state or ""
+        pill = (
+            "bg-emerald-100 text-emerald-800" if st == "confirmed"
+            else "bg-amber-100 text-amber-800" if st == "reserved"
+            else "bg-blue-100 text-blue-800" if st == "checked_in"
+            else "bg-stone-100 text-stone-700"
+        )
+        pill_cls = f"inline-flex items-center rounded-full px-2 py-0.5 text-[11px] font-medium {pill}"
+        ds = tk.entry_start_at.strftime("%-d %b %Y, %H:%M") if tk.entry_start_at else ""
+        if tk.entry_end_at:
+            ds += f" – {tk.entry_end_at.strftime('%-d %b %Y, %H:%M')}"
+        items.append(sx_call(
+            "checkout-return-ticket",
+            name=tk.entry_name,
+            pill=pill_cls,
+            state=st.replace("_", " ").capitalize(),
+            type_name=tk.ticket_type_name or None,
+            date_str=ds,
+            code=tk.code,
+            price=f"£{tk.price or 0:.2f}",
+        ))
+    items_sx = "(<> " + " ".join(items) + ")"
+    return sx_call("checkout-return-tickets", items=SxExpr(items_sx))
+
+
+async def render_checkout_return_page(ctx: dict, order: Any | None,
+                                      status: str,
+                                      calendar_entries: list | None = None,
+                                      order_tickets: list | None = None) -> str:
+    """Full page: checkout return after SumUp payment (sx wire format)."""
+    filt = sx_call("checkout-return-header", status=status)
+
+    if not order:
+        content = sx_call("checkout-return-missing")
+    else:
+        summary = sx_call(
+            "order-summary-card",
+            order_id=order.id,
+            created_at=order.created_at.strftime("%-d %b %Y, %H:%M") if order.created_at else None,
+            description=order.description, status=order.status,
+            currency=order.currency,
+            total_amount=f"{order.total_amount:.2f}" if order.total_amount else None,
+        )
+        items = _order_items_sx(order)
+        calendar = _calendar_items_sx(calendar_entries)
+        tickets = _ticket_items_sx(order_tickets)
+
+        status_msg = ""
+        if order.status == "failed":
+            status_msg = sx_call("checkout-return-failed", order_id=order.id)
+        elif order.status == "paid":
+            status_msg = sx_call("checkout-return-paid")
+
+        content = sx_call(
+            "checkout-return-content",
+            summary=SxExpr(summary),
+            items=SxExpr(items) if items else None,
+            calendar=SxExpr(calendar) if calendar else None,
+            tickets=SxExpr(tickets) if tickets else None,
+            status_message=SxExpr(status_msg) if status_msg else None,
+        )
+
+    hdr = root_header_sx(ctx)
+    inner = _auth_header_sx(ctx)
+    hdr = "(<> " + hdr + " " + header_child_sx(inner) + ")"
+
+    return full_page_sx(ctx, header_rows=hdr, filter=filt, content=content)