feat(linkedin-studio): RE-R2b — dated morning-brief artifact + session-start surfacing [skip-docs]
The visible layer of R2. Pure brief.ts: rankForBrief (pillar-overlap -> recency over
the store; publishedAt ?? capturedAt freshness, 7d window; total-order sort), renderBrief
(dated Markdown + hook-surfaceable summary frontmatter), briefSummary (one summary source),
defaultBriefDir (derived from defaultStorePath). CLI `brief` writes
<data>/trends/morning-brief/YYYY-MM-DD.md; session-start surfaces the latest zero-tsx
(latestMorningBrief). Wired into trend-spotter Step 4.6 (scan->capture->brief->surfaced).
No store-schema/scoring change; no scheduler (R3).
25 new trends tests (21 brief.test + 4 cli brief, RED-first) + 3 hook tests (morning-brief
surfacing). trends 104/104 (floor 104), hook-suite 139/139, gate FAIL=0 (ASSERT floor 94,
Section 16i: cli brief-handler + trend-spotter brief-pointer + session-start surfacing
greps), tsc clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VmHCQjJHUyWwxGAVVjNLgp