feat(runtime): stuck-incident detector + skill metrics + edit scope (Phase 6) (#17)

Phase 6 of plans/autonomous-survival-bot-prd.md. Expand the
self-improvement loop so the bot can spot and report no-progress
stagnation, not just exception-class failures.

New:
- runtime/stuck-incident.js: detector fires a structured proposal when
  the same noProgressReason persists past 5 min (cooldown 30 min).
  Body includes runtimeState, milestone, suggested skill, slim
  snapshot, last action result, per-skill success/failure metrics
  and a forbidden-paths list. Pure module — caller (bot.js) writes
  the proposal.
- runtime/skill-metrics.js: in-memory per-skill ok/fail counters
  surfaced on snapshot.skillMetrics for the TUI and the incident
  body.
- runtime/stuck-incident.test.js: 6 tests covering null reason,
  threshold gating, cooldown, reason change resetting the timer,
  body composition and metrics snapshot.

Wiring:
- runtime/state-store.js: writeProposal accepts {editScope: string[]}
  and persists it in the frontmatter; readProposalEditScope() reads
  it back so future auto-patch.js can refuse cherry-picks that touch
  other areas.
- runtime/bot.js: tick() invokes the stuck detector each tick,
  records skill ok/fail via skillMetrics, stamps snapshot.skillMetrics
  and writes the stuck proposal via writeProposal({editScope}).
  dispatchAction now records into skillMetrics for both the
  resolved-result and the exception path.

npm test now 46/46.

Co-authored-by: Yuriy Mayatnikov <mayatnikov@me.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -16,7 +16,7 @@
     "tui": "tsx tui/tui.tsx",
     "propose:apply": "node scripts/propose-apply.js",
     "stop": "bash scripts/stop.sh",
-    "test": "node --test runtime/skills/contract.test.js runtime/skills/groups.test.js runtime/curriculum.test.js runtime/social/social.test.js"
+    "test": "node --test runtime/skills/contract.test.js runtime/skills/groups.test.js runtime/curriculum.test.js runtime/social/social.test.js runtime/stuck-incident.test.js"
   },
   "dependencies": {
     "dotenv": "^16.4.5",