feat(linkedin-studio): brain emits OKF-compatible form — Stage 1 (bundle=brain/, ingest/ excluded) [skip-docs]

Cross-plugin OKF convergence, Stage 1 (docs/okf-convergence-brief.md): the
second-brain hub now conforms to OKF-compatible form so a shared retrieval
skill (and a sibling agent) can traverse it.

- serializeProfile leads with a constant `type: Profile` frontmatter block
  (round-trip-safe: parseProfile skips it, parse-serialize identity holds).
- operations.md seed -> `type: Operations`; index.md seed -> `okf_version: 0.1`
  marker (markdown text; index files carry no frontmatter per OKF); new
  brain/journal/index.md (per-level index).

Premise correction: the brain is deliberately YAML-free and ingest/published
has a byte-exact round-trip invariant (SC2) a frontmatter block would break,
so the concept-bundle is scoped to brain/ ONLY; the ingest/ tributary is
excluded and pointed to from the hub. We emit frontmatter, add no parser.

Verified: new tests/okf-conform.test.ts (5/5); full brain suite 132/132 (0
regressions); cross-tool — okr/scripts/okf-check.mjs validates brain/ (exit 0).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011vmzxpsFpc8q19LaogAWLD

scripts/brain/src/profile.ts

@@ -36,9 +36,18 @@ function serializeFact(f: ProfileFact): string {
   return f.value === "" ? `- [${bracket}]` : `- [${bracket}] ${f.value}`;
 }
 
-/** Deterministic full-document serialization; both sections always present. */
+/**
+ * Deterministic full-document serialization; both sections always present. A
+ * constant OKF frontmatter block (`type: Profile`) leads the document so the brain
+ * bundle is OKF-compatible form (docs/okf-convergence-brief.md); it carries no
+ * typed-doc data, so `parseProfile` skips it and `parse ∘ serialize` stays identity.
+ */
 export function serializeProfile(doc: ProfileDoc): string {
   const lines: string[] = [
+    "---",
+    "type: Profile",
+    "---",
+    "",
     "# Profile",
     "",
     `schemaVersion: ${doc.schemaVersion}`,

scripts/brain/src/scaffold.ts

@@ -35,6 +35,8 @@ function indexSeed(): string {
 > Map of Content — one screen pointing at every tributary, with a freshness flag.
 > Generated by \`brain init\`; safe to hand-edit (a re-run never clobbers it).
 
+okf_version: 0.1
+
 | Tributary | What it holds | Freshness |
 |-----------|---------------|-----------|
 | voice-samples | writing style | — |
@@ -50,7 +52,10 @@ function indexSeed(): string {
 }
 
 function operationsSeed(): string {
-  return `# Operations
+  return `---
+type: Operations
+---
+# Operations
 
 > The operations centre — where you're headed now, what you're working on, what you might
 > do next. User-authored: the brain motor never writes here (a re-run of init never
@@ -74,6 +79,15 @@ _As of YYYY-MM-DD:_ <one or two sentences on your current direction — replace
 `;
 }
 
+function journalIndexSeed(): string {
+  return `# Journal — episodic log
+
+> Append-only session entries (\`YYYY-MM-session.md\`). Raw, never edited — the
+> source the consolidation loop distils from. One concept per file. A reserved
+> OKF index (no frontmatter); the entries carry the \`type\`.
+`;
+}
+
 function profileSeed(): string {
   const templateText = readFileSync(TEMPLATE_PATH, "utf8");
   const instancePath = dataRoot(INSTANCE_SUB);
@@ -111,6 +125,7 @@ export function initBrain(): InitResult {
     { sub: "brain/profile.md", seed: profileSeed },
     { sub: "brain/index.md", seed: indexSeed },
     { sub: "brain/operations.md", seed: operationsSeed },
+    { sub: "brain/journal/index.md", seed: journalIndexSeed },
   ];
 
   for (const { sub, seed } of files) {