feat(linkedin-studio): brain Stage 1 finish — title/description + pending-diff typed [skip-docs]

Completes the linkedin-studio in-scope Stage 1 (docs/okf-convergence-brief.md):
- serializeProfile + operations.md seed gain the cheap recommended OKF fields
  `title` + `description` (timestamp/resource intentionally omitted — a timestamp
  would break the pure/deterministic serializer; resource is N/A internally).
- renderDiffMd leads the transient pending-diff.md with `type: PendingDiff`, so
  the brain/ bundle passes okf-check even mid-propose.

Verified: 2 new tests (okf-conform + consolidate-cli); full brain suite 134/134
(0 regressions); cross-tool — okr/scripts/okf-check.mjs validates brain/ exit 0
WITH a pending-diff present.

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

scripts/brain/src/scaffold.ts

@@ -54,6 +54,8 @@ okf_version: 0.1
 function operationsSeed(): string {
   return `---
 type: Operations
+title: Operations
+description: Plans, ideas, and the current-direction anchor - the operations centre.
 ---
 # Operations