content: document metadata (meta.sx) + Ghost title plumbing + 27 tests (365/365)

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` → **338/338** (Phases 1–4 COMPLETE + extensions: HTML/SX escaping, Markdown render+import, durable CRDT replication, validation, snapshot cache)
+`bash lib/content/conformance.sh` → **365/365** (Phases 1–4 COMPLETE + extensions: HTML/SX escaping, Markdown render+import, durable CRDT replication, validation, snapshot cache, doc metadata)
 
 ## Ground rules
 
@@ -83,9 +83,16 @@ lib/content/api.sx ── (content/edit) (content/render) (content/history) ─
 - [x] document validation (`validate.sx`: ids, per-type fields, duplicate ids)
 - [x] Markdown import adapter (`md-import.sx`: text → blocks, round-trips export)
 - [x] snapshot cache over replay (`snapshot.sx`: cache-not-primary, transparent)
+- [x] document metadata (`meta.sx`: title/slug/tags + Ghost title plumbing)
 
 ## Progress log
 
+- 2026-06-07 — Extension: document metadata (`meta.sx`). CtDoc gained optional
+  title/slug/tags ivars (declared in doc.sx, default nil/empty, no effect on
+  block ops). Reads via message dispatch; copy-on-write setters
+  (`doc-with-title/slug/tags`, `doc-add-tag`, `doc-with-meta`, `doc-new-meta`)
+  and `content/*` aliases; `doc-meta` returns the metadata dict. Ghost adapter
+  now carries `:title` through import/export/round-trip. 27 tests; suite 365/365.
 - 2026-06-07 — Extension: snapshot cache over op-log replay (`snapshot.sx`).
   Snapshots are a cache, never primary state — the log stays the source of truth.
   `content/snapshot!` stores a materialised head at a seq in the persist KV;