refactor: consolidate skill docs, add anti-drift tests, and apply audit fixes

DLO-13: Restructure vlm-library-workflow skill as safety contract layer.
- Rewrite SKILL.md (69 lines): safety contract, execution threshold semantics,
  six-step high-risk loop, decision rules, phase skeleton
- Delete redundant references (cli-reference, workflow, command-recipes, dev-guide)
- Add triage.md (failure mapping + preflight) and dev-map.md (module→test mapping)
- Add tests/test_docs_consistency.py: 78 parametrized tests verifying documented
  vlm commands exist in CLI registry
- Add CSV path mismatch test to test_plan_review.py (4th safety gate path)
- Delete vlm-expert.skill (Gemini package, 7 months stale) and README Gemini section

DLO-2 audit fixes: rate limiter injection, symmetric quarantine categories,
review-plan safety gates, parser improvements, planner validation.

CLI modularization: commands/ directory with one module per command group.

skills/vlm-library-workflow/references/triage.md

@@ -0,0 +1,23 @@
+# Triage & Preflight
+
+## Preflight Checks
+
+Before executing workflow commands:
+
+1. Confirm working directory is repository root.
+2. Run `vlm --help`; if unavailable, switch to `uv run vlm`.
+3. Run `<subcommand> --help` when options are uncertain.
+4. Run `vlm config validate` after config edits.
+5. Verify required input files exist before downstream stages.
+6. Treat `execute --confirm` as destructive; require explicit user confirmation.
+
+## Failure Triage
+
+| Problem | Command |
+|---------|---------|
+| Missing config | `vlm config init`, then set `library_root` |
+| Invalid config values | `vlm config validate` and fix reported keys |
+| Missing input artifact | Run prerequisite stage (scan → parse → analyze → plan) |
+| Unexpected duplicate decisions | Check `plan.duplicate_keep` in config, rerun `vlm plan --analysis` |
+| Unsafe execution results | `vlm rollback`, inspect plan, re-run `execute --confirm` |
+| `vlm` not found | Use `uv run vlm ...` fallback |