Move market composition from Python to .sx defcomps (Phase 8)

Convert 5 market page helpers from returning sx_call() strings to
returning data dicts. Defpages now use :data + :content pattern.
Admin panel uses inline map/fn for CRUD item composition.
Removed market-admin-content helper (placeholder inlined in defpage).

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

market/sxc/pages/market.sx

@@ -1,4 +1,5 @@
 ;; Market app defpage declarations.
+;; All helpers return data dicts — markup composition in SX.
 ;;
 ;; all-markets-index: / — global view across all pages
 ;; page-markets-index: /<slug>/ — markets for a single page
@@ -10,28 +11,64 @@
   :path "/"
   :auth :public
   :layout :root
-  :content (all-markets-content))
+  :data (all-markets-data)
+  :content (if no-markets
+    (~empty-state :icon "fa fa-store" :message "No markets available"
+      :cls "px-3 py-12 text-center text-stone-400")
+    (~market-markets-grid
+      :cards (~market-cards-content
+        :markets market-data :page market-page
+        :has-more has-more :next-url next-url))))
 
 (defpage page-markets-index
   :path "/<slug>/"
   :auth :public
   :layout :post
-  :content (page-markets-content))
+  :data (page-markets-data)
+  :content (if no-markets
+    (~empty-state :message "No markets for this page"
+      :cls "px-3 py-12 text-center text-stone-400")
+    (~market-markets-grid
+      :cards (~market-cards-content
+        :markets market-data :page market-page
+        :has-more has-more :next-url next-url))))
 
 (defpage page-admin
   :path "/<slug>/admin/"
   :auth :admin
   :layout (:post-admin :selected "markets")
-  :content (page-admin-content))
+  :data (page-admin-data)
+  :content (~market-admin-content-wrap
+    :inner (~crud-panel
+      :list-id "markets-list"
+      :form (when can-create
+        (~crud-create-form
+          :create-url create-url :csrf csrf
+          :errors-id "market-create-errors" :list-id "markets-list"
+          :placeholder "e.g. Suma, Craft Fair" :btn-label "Add market"))
+      :list (if admin-markets
+        (<> (map (fn (m)
+          (~crud-item
+            :href (get m "href") :name (get m "name") :slug (get m "slug")
+            :del-url (get m "del-url") :csrf-hdr (get m "csrf-hdr")
+            :list-id "markets-list"
+            :confirm-title "Delete market?"
+            :confirm-text "Products will be hidden (soft delete)"))
+          admin-markets))
+        (~empty-state
+          :message "No markets yet. Create one above."
+          :cls "text-gray-500 mt-4")))))
 
 (defpage market-home
   :path "/<page_slug>/<market_slug>/"
   :auth :public
   :layout :market
-  :content (market-home-content))
+  :data (market-home-data)
+  :content (~market-landing-from-data
+    :excerpt excerpt :feature-image feature-image :html html))
 
 (defpage market-admin
   :path "/<page_slug>/<market_slug>/admin/"
   :auth :admin
   :layout (:market-admin :selected "markets")
-  :content (market-admin-content))
+  :content "market admin")