feat: default codex reviews in /ship and /review (v0.9.4.0) (#256)

* feat: default codex reviews in /ship and /review with xhigh reasoning

Codex code reviews are now opt-in-once-then-always-on via a one-time
adoption prompt. When enabled, both review + adversarial run automatically
on every /ship and /review — no more choosing between them.

Key changes:
- New {{CODEX_REVIEW_STEP}} resolver centralizes Codex review logic (DRY)
- Three-state config: enabled/not-set/disabled via gstack-config
- P1 findings default to "Investigate and fix" instead of "Ship anyway"
- All reasoning bumped to xhigh (review, adversarial, consult)
- Codex review step stripped from codex-host variants (no self-invocation)
- Ship "Never ask" rule updated to accurately list quality-gate stops
- Error handling for auth, timeout, empty response (all non-blocking)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: update touchfiles test for plan-ceo-review-benefits dependency

The merge from main added plan-ceo-review-benefits to E2E_TOUCHFILES,
which means plan-ceo-review/SKILL.md now selects 3 tests, not 2.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* feat: default codex reviews in /ship and /review (v0.9.4.0)

Codex code reviews now run automatically — both review + adversarial
challenge — with a one-time opt-in prompt for new users. All modes use
xhigh reasoning. Codex-host builds strip the step to prevent recursion.

Fixes from Codex review: TMPERR properly defined, stderr captured for
both review and adversarial, error handling before log persist, commit
hash included in review log for staleness tracking.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

codex/SKILL.md

@@ -300,13 +300,13 @@ TMPERR=$(mktemp /tmp/codex-err-XXXXXX.txt)
 
 2. Run the review (5-minute timeout):
 ```bash
-codex review --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR"
+codex review --base <base> -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR"
 ```
 
 Use `timeout: 300000` on the Bash call. If the user provided custom instructions
 (e.g., `/codex review focus on security`), pass them as the prompt argument:
 ```bash
-codex review "focus on security" --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR"
+codex review "focus on security" --base <base> -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR"
 ```
 
 3. Capture the output. Then parse cost from stderr:
@@ -461,7 +461,7 @@ THE PLAN:
 
 For a **new session:**
 ```bash
-codex exec "<prompt>" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached --json 2>"$TMPERR" | python3 -c "
+codex exec "<prompt>" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached --json 2>"$TMPERR" | python3 -c "
 import sys, json
 for line in sys.stdin:
     line = line.strip()
@@ -494,7 +494,7 @@ for line in sys.stdin:
 
 For a **resumed session** (user chose "Continue"):
 ```bash
-codex exec resume <session-id> "<prompt>" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached --json 2>"$TMPERR" | python3 -c "
+codex exec resume <session-id> "<prompt>" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached --json 2>"$TMPERR" | python3 -c "
 <same python streaming parser as above>
 "
 ```
@@ -530,10 +530,7 @@ Session saved — run /codex again to continue this conversation.
 agentic coding model). This means as OpenAI ships newer models, /codex automatically
 uses them. If the user wants a specific model, pass `-m` through to codex.
 
-**Reasoning effort** varies by mode — use the right level for each task:
-- **Review mode:** `high` — thorough but not slow. Diff review benefits from depth but doesn't need maximum compute.
-- **Challenge (adversarial) mode:** `xhigh` — maximum reasoning power. When trying to break code, you want the model thinking as hard as possible.
-- **Consult mode:** `high` — good balance of depth and speed for conversations.
+**Reasoning effort:** All modes use `xhigh` — maximum reasoning power. When reviewing code, breaking code, or consulting on architecture, you want the model thinking as hard as possible.
 
 **Web search:** All codex commands use `--enable web_search_cached` so Codex can look up
 docs and APIs during review. This is OpenAI's cached index — fast, no extra cost.