Migrate all apps to defpage declarative page routes

Replace Python GET page handlers with declarative defpage definitions in .sx
files across all 8 apps (sx docs, orders, account, market, cart, federation,
events, blog). Each app now has sxc/pages/ with setup functions, layout
registrations, page helpers, and .sx defpage declarations.

Core infrastructure: add g I/O primitive, PageDef support for auth/layout/
data/content/filter/aside/menu slots, post_author auth level, and custom
layout registration. Remove ~1400 lines of render_*_page/render_*_oob
boilerplate. Update all endpoint references in routes, sx_components, and
templates to defpage_* naming.

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

account/sxc/pages/__init__.py

@@ -0,0 +1,105 @@
+"""Account defpage setup — registers layouts, page helpers, and loads .sx pages."""
+from __future__ import annotations
+
+from typing import Any
+
+
+def setup_account_pages() -> None:
+    """Register account-specific layouts, page helpers, and load page definitions."""
+    _register_account_layouts()
+    _register_account_helpers()
+    _load_account_page_files()
+
+
+def _load_account_page_files() -> None:
+    import os
+    from shared.sx.pages import load_page_dir
+    load_page_dir(os.path.dirname(__file__), "account")
+
+
+# ---------------------------------------------------------------------------
+# Layouts
+# ---------------------------------------------------------------------------
+
+def _register_account_layouts() -> None:
+    from shared.sx.layouts import register_custom_layout
+    register_custom_layout("account", _account_full, _account_oob, _account_mobile)
+
+
+def _account_full(ctx: dict, **kw: Any) -> str:
+    from shared.sx.helpers import root_header_sx, header_child_sx
+    from sx.sx_components import _auth_header_sx
+
+    root_hdr = root_header_sx(ctx)
+    hdr_child = header_child_sx(_auth_header_sx(ctx))
+    return "(<> " + root_hdr + " " + hdr_child + ")"
+
+
+def _account_oob(ctx: dict, **kw: Any) -> str:
+    from shared.sx.helpers import root_header_sx
+    from sx.sx_components import _auth_header_sx
+
+    return "(<> " + _auth_header_sx(ctx, oob=True) + " " + root_header_sx(ctx, oob=True) + ")"
+
+
+def _account_mobile(ctx: dict, **kw: Any) -> str:
+    from shared.sx.helpers import mobile_menu_sx, mobile_root_nav_sx, sx_call, SxExpr
+    from sx.sx_components import _auth_nav_mobile_sx
+    ctx = _inject_account_nav(ctx)
+    auth_section = sx_call("mobile-menu-section",
+        label="account", href="/", level=1, colour="sky",
+        items=SxExpr(_auth_nav_mobile_sx(ctx)))
+    return mobile_menu_sx(auth_section, mobile_root_nav_sx(ctx))
+
+
+def _inject_account_nav(ctx: dict) -> dict:
+    """Ensure account_nav is in ctx from g.account_nav."""
+    if "account_nav" not in ctx:
+        from quart import g
+        ctx = dict(ctx)
+        ctx["account_nav"] = getattr(g, "account_nav", "")
+    return ctx
+
+
+# ---------------------------------------------------------------------------
+# Page helpers
+# ---------------------------------------------------------------------------
+
+def _register_account_helpers() -> None:
+    from shared.sx.pages import register_page_helpers
+
+    register_page_helpers("account", {
+        "account-content": _h_account_content,
+        "newsletters-content": _h_newsletters_content,
+        "fragment-content": _h_fragment_content,
+    })
+
+
+def _h_account_content():
+    from sx.sx_components import _account_main_panel_sx
+    return _account_main_panel_sx({})
+
+
+def _h_newsletters_content():
+    from quart import g
+    d = getattr(g, "newsletters_data", None)
+    if not d:
+        from shared.sx.helpers import sx_call
+        return sx_call("account-newsletter-empty")
+    from shared.sx.page import get_template_context_sync
+    from sx.sx_components import _newsletters_panel_sx
+    # Build a minimal ctx with account_url
+    ctx = {"account_url": getattr(g, "_account_url", None)}
+    if ctx["account_url"] is None:
+        from shared.infrastructure.urls import account_url
+        ctx["account_url"] = account_url
+    return _newsletters_panel_sx(ctx, d)
+
+
+def _h_fragment_content():
+    from quart import g
+    frag = getattr(g, "fragment_page_data", None)
+    if not frag:
+        return ""
+    from sx.sx_components import _fragment_content
+    return _fragment_content(frag)

account/sxc/pages/account.sx

@@ -0,0 +1,31 @@
+;; Account app — declarative page definitions
+
+;; ---------------------------------------------------------------------------
+;; Account dashboard
+;; ---------------------------------------------------------------------------
+
+(defpage account-dashboard
+  :path "/"
+  :auth :login
+  :layout :account
+  :content (account-content))
+
+;; ---------------------------------------------------------------------------
+;; Newsletters
+;; ---------------------------------------------------------------------------
+
+(defpage newsletters
+  :path "/newsletters/"
+  :auth :login
+  :layout :account
+  :content (newsletters-content))
+
+;; ---------------------------------------------------------------------------
+;; Fragment pages (tickets, bookings, etc. from events service)
+;; ---------------------------------------------------------------------------
+
+(defpage fragment-page
+  :path "/<slug>/"
+  :auth :login
+  :layout :account
+  :content (fragment-content))