Move home/post detail/like rendering from Python to .sx defcomps

- Home page: inline shared helpers, render_to_sx("blog-home-main")
- Post detail: new ~blog-post-detail-content defcomp with data from service
- Like toggle: call render_to_sx("market-like-toggle-button") directly
- Add post_meta_data() and post_detail_data() to BlogPageService

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

blog/sx/detail.sx

@@ -36,6 +36,37 @@
       (when html-content (div :class "blog-content p-2" (~rich-text :html html-content)))))
     (div :class "pb-8")))
 
+;; ---------------------------------------------------------------------------
+;; Data-driven composition — replaces _post_main_panel_sx
+;; ---------------------------------------------------------------------------
+
+(defcomp ~blog-post-detail-content (&key slug is-draft publish-requested can-edit edit-href
+                                         is-page has-user liked like-url csrf
+                                         custom-excerpt tags authors
+                                         feature-image html-content sx-content)
+  (let* ((hx-select "#main-panel")
+         (draft-sx (when is-draft
+           (~blog-detail-draft
+             :publish-requested publish-requested
+             :edit (when can-edit
+               (~blog-detail-edit-link :href edit-href :hx-select hx-select)))))
+         (chrome-sx (when (not is-page)
+           (~blog-detail-chrome
+             :like (when has-user
+               (~blog-detail-like
+                 :like-url like-url
+                 :hx-headers (str "{\"X-CSRFToken\": \"" csrf "\"}")
+                 :heart (if liked "\u2764\ufe0f" "\U0001f90d")))
+             :excerpt (when (not (= custom-excerpt ""))
+               (~blog-detail-excerpt :excerpt custom-excerpt))
+             :at-bar (~blog-at-bar :tags tags :authors authors)))))
+    (~blog-detail-main
+      :draft draft-sx
+      :chrome chrome-sx
+      :feature-image feature-image
+      :html-content html-content
+      :sx-content sx-content)))
+
 (defcomp ~blog-meta (&key robots page-title desc canonical og-type og-title image twitter-card twitter-title)
   (<>
     (meta :name "robots" :content robots)