feat(catalog): shared OKF conformance checker + wire as cross-plugin acceptance gate

Lift okr's reference okf-check.mjs into the catalog as the single cross-plugin
acceptance gate for the OKF-compatible second-brain form (spec §3):

- scripts/okf-check.mjs (+ vendored okf-frontmatter.mjs): verdict logic
  byte-identical to okr's reference impl, English output, zero deps, self-contained.
- scripts/okf-check.test.mjs: 5 self-contained tests (temp-dir bundles).
- spec §7 + §14: the shared checker now lives here; only TS/mjs reconciliation
  remains Stage-3, not required for the gate. log.md protocol §6: conformance is
  verified by the gate, not asserted — a plugin moves to 🟢 only after passing it.

Verified: 33/33 catalog tests green (canonical glob form); verdict parity with
okr's checker on okr fixtures (positive + negative missing-type); a scaffolded
linkedin-studio brain/ validates clean (exit 0).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012GqEHp4uDiivfrAUjw4BdE

scripts/okf-check.mjs

@@ -0,0 +1,96 @@
+#!/usr/bin/env node
+// okf-check.mjs — shared OKF-compatible second-brain conformance checker.
+//
+// The single cross-plugin acceptance gate for the convention in
+// docs/okf-second-brain/spec.md. Validates one bundle root against the minimal
+// contract (spec §3):
+//   - every concept file (.md except index.md) MUST carry `type:` in frontmatter;
+//     >= 1 file without type -> exit 1, count + names the files; 0 -> exit 0.
+//   - recommended fields (resource/title/description/timestamp) -> WARNING, not error.
+//   - the bundle-root index.md's `okf_version` is echoed for human comparison
+//     (no auto-fetch — offline by design).
+//
+// Lifted faithfully from okr/scripts/okf-check.mjs (the de-facto reference
+// implementation; spec §7), with English output + a vendored frontmatter reader so
+// the catalog copy is self-contained. Verdict logic is byte-identical, so a bundle's
+// pass/fail is the same here as under okr's checker. Run per bundle root.
+// Zero npm dependencies (node: builtins).
+
+import { readdirSync, readFileSync, existsSync } from 'node:fs';
+import { join, relative } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { parseFrontmatter } from './okf-frontmatter.mjs';
+
+const RECOMMENDED = ['resource', 'title', 'description', 'timestamp'];
+
+// All concept files (.md except index.md) under root, recursively.
+function walkConcepts(root) {
+  const out = [];
+  const walk = (dir) => {
+    for (const e of readdirSync(dir, { withFileTypes: true })) {
+      const p = join(dir, e.name);
+      if (e.isDirectory()) walk(p);
+      else if (e.isFile() && e.name.endsWith('.md') && e.name !== 'index.md') out.push(p);
+    }
+  };
+  walk(root);
+  return out;
+}
+
+// Read the root's okf_version (markdown text in index.md, not frontmatter). null if absent.
+function rootOkfVersion(root) {
+  const idx = join(root, 'index.md');
+  if (!existsSync(idx)) return null;
+  const m = readFileSync(idx, 'utf8').match(/^okf_version:\s*(.+)$/m);
+  return m ? m[1].trim() : null;
+}
+
+export function checkBundle(root) {
+  const concepts = walkConcepts(root);
+  const missingType = [];
+  const warnings = [];
+  for (const f of concepts) {
+    const { get } = parseFrontmatter(readFileSync(f, 'utf8'));
+    const rel = relative(root, f);
+    if (!get('type')) {
+      missingType.push(rel);
+      continue;
+    }
+    for (const field of RECOMMENDED) {
+      if (!get(field)) warnings.push(`${rel}: missing recommended field "${field}"`);
+    }
+  }
+  return {
+    scanned: concepts.length,
+    missingType,
+    warnings,
+    okfVersion: rootOkfVersion(root),
+  };
+}
+
+// --- CLI ---
+const isMain = process.argv[1]
+  && fileURLToPath(import.meta.url) === process.argv[1];
+if (isMain) {
+  const root = process.argv[2];
+  if (!root) {
+    process.stderr.write('Usage: node okf-check.mjs <bundle-root>\n');
+    process.exit(2);
+  }
+  if (!existsSync(root)) {
+    process.stderr.write(`Bundle root does not exist: ${root}\n`);
+    process.exit(2);
+  }
+  const r = checkBundle(root);
+  const out = [];
+  out.push(`OKF check: ${root}`);
+  out.push(`  Concept files scanned: ${r.scanned}`);
+  out.push(`  ${r.missingType.length} files without type:`);
+  for (const f of r.missingType) out.push(`    - ${f}`);
+  out.push(`  okf_version: ${r.okfVersion || 'MISSING (root index without okf_version)'}`);
+  out.push(`  Warnings (recommended fields): ${r.warnings.length}`);
+  for (const w of r.warnings) out.push(`    ! ${w}`);
+  out.push(r.missingType.length === 0 ? 'OK: valid OKF bundle' : `FAIL: ${r.missingType.length} file(s) missing type:`);
+  process.stdout.write(`${out.join('\n')}\n`);
+  process.exit(r.missingType.length === 0 ? 0 : 1);
+}