content: table block (table.sx) + 15 tests (448/448)

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` → **433/433** (Phases 1–4 COMPLETE + 11 extensions: HTML/SX escaping, Markdown render+import, CRDT replication, tree-aware validation, snapshot cache, doc metadata, plain-text render, nested block trees, doc stats)
+`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)
 
 ## Ground rules
 
@@ -87,9 +87,16 @@ lib/content/api.sx ── (content/edit) (content/render) (content/history) ─
 - [x] plain-text render + excerpt (`text.sx`: asText, content/excerpt)
 - [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)
 
 ## Progress log
 
+- 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
+  nested `inject:into:`. Self-contained (no edits to block.sx/render.sx);
+  `mk-table`, `table?`, `table-headers/rows`. validate.sx gained a `table` field
+  case (headers/rows must be lists). 15 tests; suite 448/448.
 - 2026-06-07 — Extension: document statistics (`stats.sx`). `content/stats`
   returns `{:words :chars :blocks :reading-minutes}`; word/char counts derive
   from the tree-accurate `asText` projection, block count from an inline tree