fix(validate): a check that can never run is caught when the brief or plan is written

voyage-lekerepo end-to-end trial (2026-10-06), report points 2, 3, 4, 9:
11 of 13 brief criteria were NOT RUN at review with no warning in /trekbrief;
a plan `git grep` criterion passed validator, gate and three critic rounds,
then felled the run in Phase 7; the End-to-end field and Phase 7's text
search never met; a prose Verify left the test command undefined.

- criteria-runner: runnableCheck() screens a declared check without running
  it (same allowlist; an npm run script is not looked up at write time);
  /bin/bash tests/<script> allowed; the plan report carries end_to_end,
  verified when a passed criterion runs a step's End-to-end command (the
  older text form still counts).
- plan-validator 1.8: PLAN_VERIFICATION_NOT_RUNNABLE,
  PLAN_STEP_VERIFY_NOT_RUNNABLE, PLAN_END_TO_END_NOT_RUNNABLE,
  PLAN_END_TO_END_NOT_VERIFIED (the gate inherits them).
- brief-validator: BRIEF_SC_NOT_RUNNABLE warning; /trekbrief offers a
  tests/ script; brief-reviewer no longer proposes unrunnable commands.
- trekexecute: Phase 7 copies end_to_end from the runner; Verify's test
  command is its first backticked span.

Measured on the trial's own brief and plan: 11 warnings (the 11 NOT RUN),
and the plan stops on V5 git grep and the unlisted End-to-end command.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/fixtures/jsonl-schemas.md

@@ -22,7 +22,7 @@
 | trekbrief-stats | ts, task, slug, mode, interview_turns, review_iterations, brief_quality, research_topics, auto_research, auto_result, intent_approved, project_dir, order_id, order_claimed_at, order_reason | commands/trekbrief.md (orchestrator-emit Phase 7; order_* added by lib/stats/stats-append.mjs) | trekbrief.md:1124-1139 | profile, phase_models, profile_source | none |
 | trekresearch-stats | ts, question, mode, scope, engine, slug, project_dir, brief_path, dimensions, dimensions_baseline, dimensions_baseline_preserved, effort, conv_turns, empty_turns, unique_sources, agents_local, agents_external, gemini_used, confidence, contradictions, open_questions | commands/trekresearch.md (orchestrator-emit Stats tracking) | trekresearch.md:634-676 | profile, phase_models, parallel_agents, external_research_enabled, profile_source | none |
 | trekplan-stats | ts, task, mode, slug, brief_path, project_dir, codebase_size, codebase_files, agents_deployed, deep_dives, research_briefs_used, research_scout_used, critic_verdict, guardian_verdict, outcome | commands/trekplan.md (orchestrator-emit Phase 12) | trekplan.md:805-826 | profile, phase_models, parallel_agents, profile_source | none |
-| trekexecute-stats (Phase 9 record) | ts, plan, plan_type, mode, result, steps_total, steps_passed, steps_failed, steps_skipped, failed_at_step | lib/stats/stats-append.mjs (trekexecute.md Phase 9) | trekexecute.md:2325-2347 | profile, phase_models, profile_source | none |
+| trekexecute-stats (Phase 9 record) | ts, plan, plan_type, mode, result, steps_total, steps_passed, steps_failed, steps_skipped, failed_at_step | lib/stats/stats-append.mjs (trekexecute.md Phase 9) | trekexecute.md:2330-2352 | profile, phase_models, profile_source | none |
 | trekexecute-stats (autonomy events) | ts, event, known_event, payload | lib/stats/event-emit.mjs `emit()` | event-emit.mjs:78-99 | payload.profile, payload.phase_models, payload.profile_source | none |
 | trekexecute-stats (PostToolUse Bash) | ts, session_id, command_excerpt, duration_ms, success | hooks/scripts/post-bash-stats.mjs (Bash PostToolUse) | post-bash-stats.mjs:42-54 | none (hook is plugin-level, not profile-aware) | command_excerpt (CWE-212) |
 | trekreview-stats | ts, slug, verdict, counts (BLOCKER/MAJOR/MINOR/SUGGESTION), reviewed_files_count, mode, duration_ms | commands/trekreview.md (orchestrator-emit Phase 8) | trekreview.md:255 | profile, phase_models, profile_source | none |