fix: Codex hang fixes — plan visibility, stdout buffering, reasoning effort (v0.12.4.0) (#536)

* fix: unbuffer Python stdout in codex --json streaming

Python fully buffers stdout when piped (not a TTY). The
`codex exec --json | python3 -c "..."` pattern meant zero output
visible until process exit — users saw nothing for 30+ minutes.

Add PYTHONUNBUFFERED=1 env var, python3 -u flag, and flush=True
to all print() calls in all three Python parser blocks (Challenge,
Consult new session, Consult resumed session).

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

* fix: per-mode reasoning effort defaults, add --xhigh override

xhigh reasoning uses ~23x more tokens and causes 50+ minute hangs
on large context tasks (OpenAI issues #8545, #8402, #6931).

Per-mode defaults for /codex skill:
- Review: high (bounded diff, needs thoroughness)
- Challenge: high (adversarial but bounded by diff)
- Consult: medium (large context, interactive, needs speed)

Also changes all Outside Voice / adversarial codex invocations
across gstack (resolvers, gen-skill-docs) from xhigh to high.
Users can override with --xhigh flag when they want max reasoning.

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

* fix: explicit plan content embedding for codex sandbox visibility

Codex runs sandboxed to repo root (-C) and cannot access
~/.claude/plans/. The template already instructed content embedding
but wasn't explicit enough — Claude sometimes shortcut to
referencing the file path, causing Codex to waste 10+ tool calls
searching before giving up.

Strengthen the instruction to make embedding unambiguous: "embed
FULL CONTENT, do NOT reference the file path." Also extract
referenced source file paths from the plan so Codex reads them
directly instead of discovering via rg/find.

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

* fix: add --xhigh reminder to challenge and consult modes

The --xhigh override was only documented in Step 2A (review).
Steps 2B (challenge) and 2C (consult) lacked the reminder,
so the flag would silently do nothing for those modes.
Found by adversarial review.

* chore: bump version and changelog (v0.12.4.0)

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

---------

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

scripts/gen-skill-docs.ts

@@ -2196,7 +2196,7 @@ Write the full prompt (context block + instructions) to this file. Use the mode-
 
 \`\`\`bash
 TMPERR_OH=$(mktemp /tmp/codex-oh-err-XXXXXXXX)
-codex exec "$(cat "$CODEX_PROMPT_FILE")" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR_OH"
+codex exec "$(cat "$CODEX_PROMPT_FILE")" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR_OH"
 \`\`\`
 
 Use a 5-minute timeout (\`timeout: 300000\`). After the command completes, read stderr:
@@ -2280,7 +2280,7 @@ Claude's structured review already ran. Now add a **cross-model adversarial chal
 
 \`\`\`bash
 TMPERR_ADV=$(mktemp /tmp/codex-adv-XXXXXXXX)
-codex exec "Review the changes on this branch against the base branch. Run git diff origin/<base> to see the diff. Your job is to find ways this code will fail in production. Think like an attacker and a chaos engineer. Find edge cases, race conditions, security holes, resource leaks, failure modes, and silent data corruption paths. Be adversarial. Be thorough. No compliments — just the problems." -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR_ADV"
+codex exec "Review the changes on this branch against the base branch. Run git diff origin/<base> to see the diff. Your job is to find ways this code will fail in production. Think like an attacker and a chaos engineer. Find edge cases, race conditions, security holes, resource leaks, failure modes, and silent data corruption paths. Be adversarial. Be thorough. No compliments — just the problems." -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR_ADV"
 \`\`\`
 
 Set the Bash tool's \`timeout\` parameter to \`300000\` (5 minutes). Do NOT use the \`timeout\` shell command — it doesn't exist on macOS. After the command completes, read stderr:
@@ -2325,7 +2325,7 @@ Claude's structured review already ran. Now run **all three remaining passes** f
 **1. Codex structured review (if available):**
 \`\`\`bash
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
-codex review --base <base> -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR"
+codex review --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR"
 \`\`\`
 
 Set the Bash tool's \`timeout\` parameter to \`300000\` (5 minutes). Do NOT use the \`timeout\` shell command — it doesn't exist on macOS. Present output under \`CODEX SAYS (code review):\` header.
@@ -2435,7 +2435,7 @@ THE PLAN:
 
 \`\`\`bash
 TMPERR_PV=$(mktemp /tmp/codex-planreview-XXXXXXXX)
-codex exec "<prompt>" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR_PV"
+codex exec "<prompt>" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR_PV"
 \`\`\`
 
 Use a 5-minute timeout (\`timeout: 300000\`). After the command completes, read stderr:

scripts/resolvers/review.ts

@@ -292,7 +292,7 @@ Write the full prompt (context block + instructions) to this file. Use the mode-
 
 \`\`\`bash
 TMPERR_OH=$(mktemp /tmp/codex-oh-err-XXXXXXXX)
-codex exec "$(cat "$CODEX_PROMPT_FILE")" -C "$(git rev-parse --show-toplevel)" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR_OH"
+codex exec "$(cat "$CODEX_PROMPT_FILE")" -C "$(git rev-parse --show-toplevel)" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR_OH"
 \`\`\`
 
 Use a 5-minute timeout (\`timeout: 300000\`). After the command completes, read stderr:
@@ -376,7 +376,7 @@ Claude's structured review already ran. Now add a **cross-model adversarial chal
 
 \`\`\`bash
 TMPERR_ADV=$(mktemp /tmp/codex-adv-XXXXXXXX)
-codex exec "Review the changes on this branch against the base branch. Run git diff origin/<base> to see the diff. Your job is to find ways this code will fail in production. Think like an attacker and a chaos engineer. Find edge cases, race conditions, security holes, resource leaks, failure modes, and silent data corruption paths. Be adversarial. Be thorough. No compliments — just the problems." -C "$(git rev-parse --show-toplevel)" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR_ADV"
+codex exec "Review the changes on this branch against the base branch. Run git diff origin/<base> to see the diff. Your job is to find ways this code will fail in production. Think like an attacker and a chaos engineer. Find edge cases, race conditions, security holes, resource leaks, failure modes, and silent data corruption paths. Be adversarial. Be thorough. No compliments — just the problems." -C "$(git rev-parse --show-toplevel)" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR_ADV"
 \`\`\`
 
 Set the Bash tool's \`timeout\` parameter to \`300000\` (5 minutes). Do NOT use the \`timeout\` shell command — it doesn't exist on macOS. After the command completes, read stderr:
@@ -421,7 +421,7 @@ Claude's structured review already ran. Now run **all three remaining passes** f
 **1. Codex structured review (if available):**
 \`\`\`bash
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
-codex review --base <base> -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR"
+codex review --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR"
 \`\`\`
 
 Set the Bash tool's \`timeout\` parameter to \`300000\` (5 minutes). Do NOT use the \`timeout\` shell command — it doesn't exist on macOS. Present output under \`CODEX SAYS (code review):\` header.
@@ -531,7 +531,7 @@ THE PLAN:
 
 \`\`\`bash
 TMPERR_PV=$(mktemp /tmp/codex-planreview-XXXXXXXX)
-codex exec "<prompt>" -C "$(git rev-parse --show-toplevel)" -s read-only -c 'model_reasoning_effort="xhigh"' --enable web_search_cached 2>"$TMPERR_PV"
+codex exec "<prompt>" -C "$(git rev-parse --show-toplevel)" -s read-only -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR_PV"
 \`\`\`
 
 Use a 5-minute timeout (\`timeout: 300000\`). After the command completes, read stderr: