host: typed Ghost import — POST /import lands old posts as first-class Articles

The genesis-import seam for the loops/radar migration (NOTE-blog-types-for-radar.md):
an old Ghost post lands not as bare sx_content but as a TYPED Article.

- host/blog-import-post!(ghost-dict): put! the {slug,title,sx_content,status} record +
  is-a article + Ghost columns -> article :field-values (custom_excerpt->subtitle,
  feature_image->hero) + tags -> tag-posts with tagged edges. Idempotent. The Ghost body
  is already sx_content ((~kg_cards/kg-*) from the Python lexical_to_sx migration), so we
  carry it as-is. host/blog-import-all! for batches.
- POST /import (guarded): body = a text/sx LIST of Ghost column dicts (radar's Postgres
  reader serialises rows to this); imports each typed; -> {:ok true :data {:imported N
  :slugs (...)}}. Runs in the serving handler (IO resolver installed) so the per-post/
  per-tag loops are JIT-safe.

Verified live-path end-to-end (ephemeral SX_SERVING_JIT=1): POST a fixture Ghost post ->
imported 1; the post's edit form is pre-filled (subtitle='An imported standfirst',
hero=the feature image), its page renders the subtitle standfirst via the article template
+ the body, and its tags (News/SX) land in the graph. Tests added; full blog suite still
blocked by box contention.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/host/blog.sx

@@ -1281,6 +1281,48 @@
               (concat host/blog-rel-kinds (list (get host/blog--rel-cache slug)))))))
       (dream-redirect "/meta"))))
 
+;; ── typed Ghost import (the radar genesis-import seam) ──────────────
+;; Import ONE Ghost post (a dict of its columns, string keys) as a TYPED host post:
+;; the {slug,title,sx_content,status} record + is-a article + Ghost columns mapped onto
+;; article :field-values (custom_excerpt->subtitle, feature_image->hero) + tags landed as
+;; tag-posts with tagged edges. The Ghost body is ALREADY sx_content (the Python
+;; lexical_to_sx migration produced (~kg_cards/kg-*) markup), so we just carry it. So an
+;; old Ghost post lands not as bare markup but as a first-class typed Article — fields on
+;; the edit form, subtitle as a rendered standfirst, tags in the graph. Idempotent
+;; (put!/seed!/relate! are sets). Contract: plans/NOTE-blog-types-for-radar.md.
+(define host/blog-import-post!
+  (fn (gp)
+    (let ((slug (get gp "slug")) (title (get gp "title")))
+      (begin
+        (host/blog-put! slug title (or (get gp "sx_content") "") (or (get gp "status") "published"))
+        (host/blog-relate! slug "article" "is-a")
+        (host/blog--set-field-values! slug
+          {"subtitle" (or (get gp "custom_excerpt") (get gp "excerpt") "")
+           "hero" (or (get gp "feature_image") "")})
+        (for-each
+          (fn (tag)
+            (let ((tslug (host/blog-slugify tag)))
+              (begin
+                (host/blog-seed! tslug tag (str "(article (h1 \"" tag "\"))") "published")
+                (host/blog-relate! tslug "tag" "is-a")
+                (host/blog-relate! slug tslug "tagged"))))
+          (or (get gp "tags") (list)))
+        slug))))
+;; Import a batch; returns the imported slugs.
+(define host/blog-import-all!
+  (fn (posts) (map host/blog-import-post! posts)))
+;; POST /import — the genesis-import endpoint. Body = a text/sx LIST of Ghost post dicts
+;; (radar's Postgres reader serialises rows to this); imports each as a typed post.
+;; -> {:ok true :data {:imported N :slugs (...)}}. Guarded (admin). Runs in the serving
+;; handler (IO resolver installed) so the per-post / per-tag loops are JIT-safe.
+(define host/blog-import-handler
+  (fn (req)
+    (let ((raw (dream-body req)))
+      (let ((posts (if (or (nil? raw) (= raw "")) (list) (sxtp/-normalize (parse-safe raw)))))
+        (if (= (type-of posts) "list")
+          (host/ok {:imported (len posts) :slugs (host/blog-import-all! posts)})
+          (host/error 400 "expected a text/sx list of Ghost post dicts"))))))
+
 ;; GET /<slug>/source — the raw sx_content as text/plain. Posts ARE SX source, so
 ;; this just hands back the stored markup (public; a published post's source is
 ;; not secret). 404 if the post is absent.
@@ -1541,7 +1583,8 @@
       (dream-post "/:slug/relate" (host/blog--protect-html resolve host/blog-relate-submit))
       (dream-post "/:slug/unrelate" (host/blog--protect-html resolve host/blog-unrelate-submit))
       (dream-post "/meta/new-type" (host/blog--protect-html resolve host/blog-meta-new-type))
-      (dream-post "/meta/new-relation" (host/blog--protect-html resolve host/blog-meta-new-relation)))))
+      (dream-post "/meta/new-relation" (host/blog--protect-html resolve host/blog-meta-new-relation))
+      (dream-post "/import" (host/blog--protect-html resolve host/blog-import-handler)))))
 
 ;; EXPERIMENTAL: create-only, UNGUARDED — POST /new form ingest with error
 ;; trapping but NO auth, for validating the editor->host publish loop on the