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>

market/sx/layouts.sx

@@ -1,42 +1,105 @@
-;; Market layout defcomps — root header via ~root-header-auto,
-;; market-specific headers passed as &key params.
+;; Market layout defcomps — fully self-contained via IO primitives.
+;; Registered via register_sx_layout in layouts.py.
 
-;; --- Browse layout: root + post header + market header ---
+;; ---------------------------------------------------------------------------
+;; Auto-fetching market header macro
+;; ---------------------------------------------------------------------------
 
-(defcomp ~market-browse-layout-full (&key post-header market-header)
+(defmacro ~market-header-auto (oob)
+  "Market header row using (market-header-ctx)."
+  (quasiquote
+    (let ((__mctx (market-header-ctx)))
+      (~menu-row-sx :id "market-row" :level 2
+        :link-href (get __mctx "link-href")
+        :link-label-content (~market-shop-label
+          :title (get __mctx "market-title")
+          :top-slug (get __mctx "top-slug")
+          :sub-div (get __mctx "sub-slug"))
+        :nav (get __mctx "desktop-nav")
+        :child-id "market-header-child"
+        :oob (unquote oob)))))
+
+;; ---------------------------------------------------------------------------
+;; OOB clear helpers
+;; ---------------------------------------------------------------------------
+
+(defcomp ~market-clear-oob ()
+  "Clear OOB divs for browse level."
+  (<>
+    (~clear-oob-div :id "product-admin-row")
+    (~clear-oob-div :id "product-admin-header-child")
+    (~clear-oob-div :id "product-row")
+    (~clear-oob-div :id "product-header-child")
+    (~clear-oob-div :id "market-admin-row")
+    (~clear-oob-div :id "market-admin-header-child")
+    (~clear-oob-div :id "post-admin-row")
+    (~clear-oob-div :id "post-admin-header-child")))
+
+(defcomp ~market-clear-oob-admin ()
+  "Clear OOB divs for admin level."
+  (<>
+    (~clear-oob-div :id "product-admin-row")
+    (~clear-oob-div :id "product-admin-header-child")
+    (~clear-oob-div :id "product-row")
+    (~clear-oob-div :id "product-header-child")))
+
+;; ---------------------------------------------------------------------------
+;; Browse layout: root + post + market (self-contained)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~market-browse-layout-full ()
   (<> (~root-header-auto)
-    (~header-child-sx :inner (<> post-header market-header))))
+    (~header-child-sx
+      :inner (<> (~post-header-auto nil)
+               (~market-header-auto nil)))))
 
-(defcomp ~market-browse-layout-oob (&key oob-header post-header-oob clear-oob)
-  (<> oob-header post-header-oob clear-oob))
+(defcomp ~market-browse-layout-oob ()
+  (<> (~post-header-auto true)
+    (~oob-header-sx :parent-id "post-header-child"
+      :row (~market-header-auto nil))
+    (~market-clear-oob)
+    (~root-header-auto true)))
 
-;; --- Product layout: root + post + market + product ---
+(defcomp ~market-browse-layout-mobile ()
+  (let ((__mctx (market-header-ctx)))
+    (get __mctx "mobile-nav")))
 
+;; ---------------------------------------------------------------------------
+;; Market admin layout: root + post + market + post-admin (self-contained)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~market-admin-layout-full (&key selected)
+  (<> (~root-header-auto)
+    (~header-child-sx
+      :inner (<> (~post-header-auto nil)
+               (~market-header-auto nil)
+               (~post-admin-header-auto nil selected)))))
+
+(defcomp ~market-admin-layout-oob (&key selected)
+  (<> (~market-header-auto true)
+    (~oob-header-sx :parent-id "market-header-child"
+      :row (~post-admin-header-auto nil selected))
+    (~market-clear-oob-admin)
+    (~root-header-auto true)))
+
+;; ---------------------------------------------------------------------------
+;; Parameterized defcomps — used by renders.py (non-defpage routes)
+;; ---------------------------------------------------------------------------
+
+;; Product layout: root + post + market + product
 (defcomp ~market-product-layout-full (&key post-header market-header product-header)
   (<> (~root-header-auto)
     (~header-child-sx :inner (<> post-header market-header product-header))))
 
-;; --- Product admin layout: root + post + market + product + admin ---
-
+;; Product admin layout: root + post + market + product + admin
 (defcomp ~market-product-admin-layout-full (&key post-header market-header product-header admin-header)
   (<> (~root-header-auto)
     (~header-child-sx :inner (<> post-header market-header product-header admin-header))))
 
-;; --- Market admin layout: root + post + market + market-admin ---
-
-(defcomp ~market-admin-layout-full (&key post-header market-header admin-header)
-  (<> (~root-header-auto)
-    (~header-child-sx :inner (<> post-header market-header admin-header))))
-
-(defcomp ~market-admin-layout-oob (&key market-header-oob admin-oob-header clear-oob)
-  (<> market-header-oob admin-oob-header clear-oob))
-
-;; --- OOB wrappers ---
-
+;; OOB wrappers
 (defcomp ~market-oob-wrap (&key parts)
   (<> parts))
 
-;; --- Content wrappers ---
-
+;; Content wrappers
 (defcomp ~market-content-padded (&key content)
   (<> content (div :class "pb-8")))