content: HTML page wrapper (page.sx) + 7 tests (455/455)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plans/content-on-sx.md

@@ -19,7 +19,7 @@ injected adapter, not core.
 
 ## Status (rolling)
 
-`bash lib/content/conformance.sh` → **448/448** (Phases 1–4 COMPLETE + 12 extensions: HTML/SX escaping, Markdown render+import, CRDT replication, tree-aware validation, snapshot cache, doc metadata, plain-text render, nested block trees, doc stats, table block)
+`bash lib/content/conformance.sh` → **455/455** (Phases 1–4 COMPLETE + 13 extensions: HTML/SX escaping, Markdown render+import, CRDT replication, tree-aware validation, snapshot cache, doc metadata, plain-text render, nested block trees, doc stats, table block, HTML page wrapper)
 
 ## Ground rules
 
@@ -88,9 +88,15 @@ lib/content/api.sx ── (content/edit) (content/render) (content/history) ─
 - [x] nested block trees (`section.sx`: CtSection container, recursive render, deep-find)
 - [x] document statistics (`stats.sx`: word/char/block counts, reading time)
 - [x] table block (`table.sx`: CtTable, renders html/sx/text/md, validated)
+- [x] HTML page wrapper (`page.sx`: content/page, escaped title from metadata)
 
 ## Progress log
 
+- 2026-06-07 — Extension: HTML page wrapper (`page.sx`). `content/page` composes
+  metadata + render into a minimal valid HTML5 document — escaped `<title>` from
+  doc metadata (falling back to id) and the rendered blocks as the body.
+  `content/page-title`. The shippable artifact the blog serves. 7 tests; suite
+  455/455.
 - 2026-06-07 — Extension: table block (`table.sx`). `CtTable` holds headers +
   rows (string lists); answers asHTML (escaped `<table>`), asSx, asText, and
   asMarkdown: (pipe table with dashed separator row) by folding rows×cells via