feat(do-task): add do-task skill with dual-loop review

M7 final — adds CLI version checks (claude --version, codex --version)
to the claude-code and codex Prerequisite Check sections so docs and
skill requirements agree. This addresses the only P3 finding from
the M7 review (non-blocking docs-to-skill mismatch).

All 7 milestones delivered across 6 local commits:
- 437b202 M1+M2: claude-code canonical + M1 canonical specs
- d69da3a M3: codex variant
- f404792 M4: cursor variant
- f5161f5 M5: opencode variant
- 9853d49 M6: docs/DO-TASK.md + README updates
- this commit (M7): final gate + P3 fix

do-task ships four runtime variants (claude-code, codex, cursor,
opencode) that execute a single user-supplied prompt end-to-end
with:
- Plan review loop and implementation review loop, each against a
  reviewer CLI (codex, claude, cursor, or opencode) with up to
  MAX_ROUNDS=10 revisions until APPROVED.
- Parameterized shared Review Loop subroutine (9 steps) invoked
  twice per run with loop-distinct session IDs so reviewer context
  never leaks across loops.
- Per-payload secret scan (10 anchored regexes; no caching) with
  redacted-only user surfacing (`[REDACTED:<label>:<n>-chars]`).
- TDD-first execution via superpowers:test-driven-development with
  strict auto-skip limited to pure-documentation and
  pure-comment-whitespace-rename.
- Verification gate (lint/typecheck/tests) before the
  implementation review loop.
- Single task commit after implementation APPROVED; explicit "yes"
  required to push.
- Telegram notification on every terminal outcome.
- Persistent ai_plan/YYYY-MM-DD-<slug>/task-plan.md with 10-value
  Status enum and resume semantics.

Reviewer: codex / gpt-5.4. Total review rounds across the 7
milestones: 3+1+1+1+2+1 = 9.

M7 smoke checks (all passing):
- YAML frontmatter: 4/4 parse.
- Core-section schema: 4/4 identical (14 sections, 10 Status enum
  values, 15 Runtime State keys).
- docs/DO-TASK.md links resolve.
- 4 variant Phase 1-10 dry-runs coherent; subroutine invoked from
  Phases 5 and 8 with distinct SESSION_ID_VAR per loop.
- Opencode reviewer branch passes `bash -n` on rendered Round-1,
  Round-N (fresh-call), and Round-N (resume) templates.
- Resume-state walk through Phase 4 reads all 6 session-id keys
  correctly.
- Trigger audit: "implement this" only as exclusion; dropped
  phrases only under "Dropped defaults".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

skills/do-task/claude-code/SKILL.md

@@ -12,6 +12,7 @@ This is a single-artifact sibling of `create-plan` + `implement-plan`. Unlike `i
 ## Prerequisite Check (MANDATORY)
 
 Required:
+- Claude Code CLI: `claude --version`
 - Superpowers repo: `https://github.com/obra/superpowers`
 - `superpowers:brainstorming`
 - `superpowers:test-driven-development`

skills/do-task/codex/SKILL.md

@@ -14,6 +14,7 @@ This is a single-artifact sibling of `create-plan` + `implement-plan`. Unlike `i
 ## Prerequisite Check (MANDATORY)
 
 Required:
+- Codex CLI: `codex --version`
 - Superpowers repo: `https://github.com/obra/superpowers`
 - Superpowers skills symlink: `~/.agents/skills/superpowers -> ~/.codex/superpowers/skills`
 - `superpowers:brainstorming`