host: experimental unguarded create-only POST /new — editor publishes live, 173/173

host/blog-open-create-routes mounts POST /new with error-trapping but NO auth
(create-only; no PUT/DELETE), so the SX editor can publish to the host
end-to-end on the experimental subdomain. VALIDATED LIVE: editor-style
form-urlencoded POST -> 303 -> post renders at /<slug>/ and lists on /.

Deliberate short-lived public write hole (create-only, obscure subdomain).
MUST be gated before real use: Caddy basicauth on /new, or session auth.
Swap host/blog-open-create-routes -> host/blog-write-routes <resolver> to gate.

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

lib/host/blog.sx

@@ -199,3 +199,11 @@
       (dream-post "/posts" (host/blog--protect resolve host/blog-create))
       (dream-put "/posts/:slug" (host/blog--protect resolve host/blog-update-handler))
       (dream-delete "/posts/:slug" (host/blog--protect resolve host/blog-delete-handler)))))
+
+;; EXPERIMENTAL: create-only, UNGUARDED — POST /new form ingest with error
+;; trapping but NO auth, for validating the editor->host publish loop on the
+;; experimental subdomain. Create-only by design (no PUT/DELETE), so the worst
+;; case is junk posts, not overwrite/delete. GATE before any real use.
+(define host/blog-open-create-routes
+  (list
+    (dream-post "/new" (host/pipeline (list host/wrap-errors) host/blog-form-submit))))