feat: Session Intelligence Layer — /checkpoint + /health + context recovery (v0.15.0.0) (#733) * feat: session timeline binaries (gstack-timeline-log + gstack-timeline-read) New binaries for the Session Intelligence Layer. gstack-timeline-log appends JSONL events to ~/.gstack/projects/$SLUG/timeline.jsonl. gstack-timeline-read reads, filters, and formats timeline data for /retro consumption. Timeline is local-only project intelligence, never sent anywhere. Always-on regardless of telemetry setting. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat: preamble context recovery + timeline events + predictive suggestions Layers 1-3 of the Session Intelligence Layer: - Timeline start/complete events injected into every skill via preamble - Context recovery (tier 2+): lists recent CEO plans, checkpoints, reviews - Cross-session injection: LAST_SESSION and LATEST_CHECKPOINT for branch - Predictive skill suggestion from recent timeline patterns - Welcome back message synthesis - Routing rules for /checkpoint and /health Timeline writes are NOT gated by telemetry (local project intelligence). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat: /checkpoint + /health skills (Layers 4-5) /checkpoint: save/resume/list working state snapshots. Supports cross-branch listing for Conductor workspace handoff. Session duration tracking. /health: code quality scorekeeper. Wraps project tools (tsc, biome, knip, shellcheck, tests), computes composite 0-10 score, tracks trends over time. Auto-detects tools or reads from CLAUDE.md ## Health Stack. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * chore: regenerate SKILL.md files + add timeline tests 9 timeline tests (all passing) mirroring learnings.test.ts pattern. All 34 SKILL.md files regenerated with new preamble (context recovery, timeline events, routing rules for /checkpoint and /health). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * chore: bump version and changelog (v0.15.0.0) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * docs: update self-learning roadmap post-Session Intelligence R1-R3 marked shipped with actual versions. R4 becomes Adaptive Ceremony (trust as separate policy engine, scope-aware, gradual degradation). R5 becomes /autoship (resumable state machine, not linear chain). R6-R7 unbundled from old R5. Added State Systems reference, Risk Register (Codex-reviewed), and validation metrics for R4. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * test: E2E tests for Session Intelligence (timeline, recovery, checkpoint) 3 gate-tier E2E tests: - timeline-event-flow: binary data flow round-trip (no LLM) - context-recovery-artifacts: seeded artifacts appear in preamble - checkpoint-save-resume: checkpoint file created with YAML frontmatter Also fixes package.json version sync (0.14.6.0 → 0.15.0.0). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>