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>

blog/sx/layouts.sx

@@ -1,4 +1,5 @@
 ;; Blog layout defcomps — fully self-contained via IO primitives.
+;; Registered via register_sx_layout in __init__.py.
 
 ;; --- Blog header (invisible row for blog-header-child swap target) ---
 
@@ -7,28 +8,161 @@
     :link-label-content (div)
     :child-id "blog-header-child" :oob oob))
 
-;; --- Blog layout (root + blog header) ---
+;; --- Auto-fetching settings header macro ---
+
+(defmacro ~blog-settings-header-auto (oob)
+  (quasiquote
+    (~menu-row-sx :id "root-settings-row" :level 1
+      :link-href (url-for "settings.defpage_settings_home")
+      :link-label-content (~blog-admin-label)
+      :nav (~blog-settings-nav)
+      :child-id "root-settings-header-child"
+      :oob (unquote oob))))
+
+;; --- Auto-fetching sub-settings header macro ---
+
+(defmacro ~blog-sub-settings-header-auto (row-id child-id endpoint icon label oob)
+  (quasiquote
+    (~menu-row-sx :id (unquote row-id) :level 2
+      :link-href (url-for (unquote endpoint))
+      :link-label-content (~blog-sub-settings-label
+        :icon (str "fa fa-" (unquote icon))
+        :label (unquote label))
+      :child-id (unquote child-id)
+      :oob (unquote oob))))
+
+;; ---------------------------------------------------------------------------
+;; Blog layout (root + blog header)
+;; ---------------------------------------------------------------------------
 
 (defcomp ~blog-layout-full ()
   (<> (~root-header-auto)
     (~blog-header)))
 
-;; --- Settings layout (root + settings header) ---
+(defcomp ~blog-layout-oob ()
+  (<> (~blog-header :oob true)
+    (~clear-oob-div :id "blog-header-child")
+    (~root-header-auto true)))
 
-(defcomp ~settings-layout-full (&key settings-header)
+;; ---------------------------------------------------------------------------
+;; Settings layout (root + settings header)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-settings-layout-full ()
   (<> (~root-header-auto)
-    settings-header))
+    (~blog-settings-header-auto)))
 
-;; --- Sub-settings layout (root + settings + sub row) ---
+(defcomp ~blog-settings-layout-oob ()
+  (<> (~blog-settings-header-auto true)
+    (~clear-oob-div :id "root-settings-header-child")
+    (~root-header-auto true)))
 
-(defcomp ~sub-settings-layout-full (&key settings-header sub-header)
+(defcomp ~blog-settings-layout-mobile ()
+  (~blog-settings-nav))
+
+;; ---------------------------------------------------------------------------
+;; Cache layout (root + settings + cache sub-header)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-cache-layout-full ()
   (<> (~root-header-auto)
-    settings-header sub-header))
+    (~blog-settings-header-auto)
+    (~blog-sub-settings-header-auto
+      "cache-row" "cache-header-child"
+      "settings.defpage_cache_page" "refresh" "Cache")))
 
-(defcomp ~sub-settings-layout-oob (&key settings-header-oob sub-header-oob)
-  (<> settings-header-oob sub-header-oob))
+(defcomp ~blog-cache-layout-oob ()
+  (<> (~blog-sub-settings-header-auto
+        "cache-row" "cache-header-child"
+        "settings.defpage_cache_page" "refresh" "Cache" true)
+    (~clear-oob-div :id "cache-header-child")
+    (~blog-settings-header-auto true)
+    (~root-header-auto true)))
 
-;; --- Settings nav links — uses (select-colours) IO primitive ---
+;; ---------------------------------------------------------------------------
+;; Snippets layout (root + settings + snippets sub-header)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-snippets-layout-full ()
+  (<> (~root-header-auto)
+    (~blog-settings-header-auto)
+    (~blog-sub-settings-header-auto
+      "snippets-row" "snippets-header-child"
+      "snippets.defpage_snippets_page" "puzzle-piece" "Snippets")))
+
+(defcomp ~blog-snippets-layout-oob ()
+  (<> (~blog-sub-settings-header-auto
+        "snippets-row" "snippets-header-child"
+        "snippets.defpage_snippets_page" "puzzle-piece" "Snippets" true)
+    (~clear-oob-div :id "snippets-header-child")
+    (~blog-settings-header-auto true)
+    (~root-header-auto true)))
+
+;; ---------------------------------------------------------------------------
+;; Menu Items layout (root + settings + menu-items sub-header)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-menu-items-layout-full ()
+  (<> (~root-header-auto)
+    (~blog-settings-header-auto)
+    (~blog-sub-settings-header-auto
+      "menu_items-row" "menu_items-header-child"
+      "menu_items.defpage_menu_items_page" "bars" "Menu Items")))
+
+(defcomp ~blog-menu-items-layout-oob ()
+  (<> (~blog-sub-settings-header-auto
+        "menu_items-row" "menu_items-header-child"
+        "menu_items.defpage_menu_items_page" "bars" "Menu Items" true)
+    (~clear-oob-div :id "menu_items-header-child")
+    (~blog-settings-header-auto true)
+    (~root-header-auto true)))
+
+;; ---------------------------------------------------------------------------
+;; Tag Groups layout (root + settings + tag-groups sub-header)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-tag-groups-layout-full ()
+  (<> (~root-header-auto)
+    (~blog-settings-header-auto)
+    (~blog-sub-settings-header-auto
+      "tag-groups-row" "tag-groups-header-child"
+      "blog.tag_groups_admin.defpage_tag_groups_page" "tags" "Tag Groups")))
+
+(defcomp ~blog-tag-groups-layout-oob ()
+  (<> (~blog-sub-settings-header-auto
+        "tag-groups-row" "tag-groups-header-child"
+        "blog.tag_groups_admin.defpage_tag_groups_page" "tags" "Tag Groups" true)
+    (~clear-oob-div :id "tag-groups-header-child")
+    (~blog-settings-header-auto true)
+    (~root-header-auto true)))
+
+;; ---------------------------------------------------------------------------
+;; Tag Group Edit layout (root + settings + tag-groups sub-header with id)
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-tag-group-edit-layout-full ()
+  (<> (~root-header-auto)
+    (~blog-settings-header-auto)
+    (~menu-row-sx :id "tag-groups-row" :level 2
+      :link-href (url-for "blog.tag_groups_admin.defpage_tag_group_edit"
+                          :id (request-view-args "id"))
+      :link-label-content (~blog-sub-settings-label
+        :icon "fa fa-tags" :label "Tag Groups")
+      :child-id "tag-groups-header-child")))
+
+(defcomp ~blog-tag-group-edit-layout-oob ()
+  (<> (~menu-row-sx :id "tag-groups-row" :level 2
+        :link-href (url-for "blog.tag_groups_admin.defpage_tag_group_edit"
+                            :id (request-view-args "id"))
+        :link-label-content (~blog-sub-settings-label
+          :icon "fa fa-tags" :label "Tag Groups")
+        :child-id "tag-groups-header-child"
+        :oob true)
+    (~clear-oob-div :id "tag-groups-header-child")
+    (~blog-settings-header-auto true)
+    (~root-header-auto true)))
+
+;; --- Settings nav links — uses IO primitives ---
 
 (defcomp ~blog-settings-nav ()
   (let* ((sc (select-colours))