Convert all 23 register_custom_layout calls to register_sx_layout across 6 services

Layout defcomps are now fully self-contained via IO-primitive auto-fetch
macros, eliminating Python layout functions that manually threaded context
values through SxExpr wrappers.

Services converted:
- Federation (1 layout): social
- Blog (7 layouts): blog, blog-settings, blog-cache, blog-snippets,
  blog-menu-items, blog-tag-groups, blog-tag-group-edit
- SX docs (2 layouts): sx, sx-section
- Cart (2 layouts): cart-page, cart-admin + orders/order-detail
- Events (9 layouts): calendar-admin, slots, slot, day-admin, entry,
  entry-admin, ticket-types, ticket-type, markets
- Market (2 layouts): market, market-admin

New IO primitives added to shared/sx/primitives_io.py:
- federation-actor-ctx, cart-page-ctx, request-view-args
- events-calendar-ctx, events-day-ctx, events-entry-ctx,
  events-slot-ctx, events-ticket-type-ctx
- market-header-ctx (pre-builds desktop/mobile nav as SxExpr)

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

federation/sx/layouts.sx

@@ -1,17 +1,17 @@
-;; Federation layout defcomps — read ctx values from env free variables.
-;; `actor` is injected into env by the layout registration in __init__.py.
+;; Federation layout defcomps — fully self-contained via IO primitives.
+;; Registered via register_sx_layout("social", ...) in __init__.py.
 
 ;; Full page: root header + social header in header-child
 (defcomp ~social-layout-full ()
   (<> (~root-header-auto)
     (~header-child-sx
       :inner (~federation-social-header
-               :nav (~federation-social-nav :actor actor)))))
+               :nav (~federation-social-nav :actor (federation-actor-ctx))))))
 
 ;; OOB (HTMX): social header oob + root header oob
 (defcomp ~social-layout-oob ()
   (<> (~oob-header-sx
         :parent-id "root-header-child"
         :row (~federation-social-header
-               :nav (~federation-social-nav :actor actor)))
+               :nav (~federation-social-nav :actor (federation-actor-ctx))))
     (~root-header-auto true)))

federation/sxc/pages/__init__.py

@@ -15,6 +15,5 @@ def _load_federation_page_files() -> None:
 
 
 def _register_federation_layouts() -> None:
-    from shared.sx.layouts import register_custom_layout
-    from .utils import _social_full, _social_oob
-    register_custom_layout("social", _social_full, _social_oob)
+    from shared.sx.layouts import register_sx_layout
+    register_sx_layout("social", "social-layout-full", "social-layout-oob")

federation/sxc/pages/utils.py

@@ -1,8 +1,6 @@
 """Federation page utilities — serializers, actor helpers, social page builder."""
 from __future__ import annotations
 
-from typing import Any
-
 
 def _serialize_actor(actor) -> dict | None:
     """Serialize an actor profile to a dict for sx defcomps."""
@@ -24,7 +22,7 @@ def _serialize_remote_actor(a) -> dict:
 
 async def _social_page(ctx: dict, actor, *, content: str,
                        title: str = "Rose Ash", meta_html: str = "") -> str:
-    """Build a full social page with social header."""
+    """Build a full social page with social header (non-defpage routes)."""
     from shared.sx.helpers import render_to_sx_with_env, full_page_sx
     from markupsafe import escape
 
@@ -47,22 +45,3 @@ def _require_actor():
     if not actor:
         abort(403, "You need to choose a federation username first")
     return actor
-
-
-def _actor_data(ctx: dict) -> dict | None:
-    actor = ctx.get("actor")
-    if not actor:
-        return None
-    return _serialize_actor(actor)
-
-
-async def _social_full(ctx: dict, **kw: Any) -> str:
-    from shared.sx.helpers import render_to_sx_with_env
-    env = {"actor": kw.get("actor") or _actor_data(ctx)}
-    return await render_to_sx_with_env("social-layout-full", env)
-
-
-async def _social_oob(ctx: dict, **kw: Any) -> str:
-    from shared.sx.helpers import render_to_sx_with_env
-    env = {"actor": kw.get("actor") or _actor_data(ctx)}
-    return await render_to_sx_with_env("social-layout-oob", env)