host: blog published-post read endpoint GET /<slug>/ -> HTML, 156/156

lib/host/blog.sx serves blog posts as HTML at GET /<slug>/ (the original
strangler target, Quart blog post_detail). A post is a content-on-sx CtDoc
rendered via content/html; anonymous + world-visible. In-memory slug->doc
registry now (host/blog-lookup swappable for a persist-backed content stream
later, handler/route unchanged). :slug catch-all mounted LAST so /feed,
/health, /internal/* take precedence. Needs the Smalltalk+persist+content
preload chain + (st-bootstrap-classes!)+(content/bootstrap!) — blog.sx
self-bootstraps at load. serve.sh loads the chain + seeds a welcome post.
Ledger gains the migrated blog post-detail (off-Quart 50% -> 53%).

LIVE: blog.rose-ash.com/welcome/ renders real HTML through Cloudflare->Caddy;
/feed still JSON (precedence verified), unknown slug 404.

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

lib/host/ledger.sx

@@ -27,6 +27,7 @@
 (define host/ledger
   (list
     (host/ledger-entry "host"      "GET"  "/health"                     nil                         "native"   "host/health-route")
+    (host/ledger-entry "blog"      "GET"  "/:slug"                      "blog:post_detail"          "migrated" "host/blog-post")
     (host/ledger-entry "feed"      "GET"  "/feed"                       "feed:timeline"             "migrated" "host/feed-timeline")
     (host/ledger-entry "feed"      "POST" "/feed"                       "feed:create"               "migrated" "host/feed-create")
     (host/ledger-entry "relations" "GET"  "/internal/data/get-children"  "relations:get_children"  "migrated" "host/relations-children")