pr-codex-bot: enforce review-before-push ordering

[aider4ryder]

Problem

The pr-codex-bot skill defines Step 2 (local pre-PR review via csa review --branch main) as happening BEFORE Step 3 (push + create PR). However, there is no enforcement mechanism to prevent the orchestrator from pushing the branch before the review completes.

In practice, the orchestrator may push the feature branch first (e.g., to get it on the remote as a working backup), then invoke pr-codex-bot, which starts the review. While the review can still catch issues before PR creation, the ordering violation means:

1. Unreviewed code is already on the remote — reviewers or CI could act on it prematurely
2. The "PRECONDITION: REVIEW_COMPLETED=true" on Step 3 is a documentation constraint but not a runtime gate

Observed Behavior

1. Agent commits on feat/optional-opencc
2. Agent runs `git push -u origin feat/optional-opencc`  ← BEFORE review
3. Agent invokes /pr-codex-bot
4. pr-codex-bot Step 2: csa review --branch main  ← happens AFTER push
5. Step 3: create PR

Expected Behavior

1. Agent commits on feat/optional-opencc
2. Agent invokes /pr-codex-bot
3. pr-codex-bot Step 2: csa review --branch main  ← BEFORE push
4. Step 3: git push + create PR  ← AFTER review passes

Suggested Fix

Options (not mutually exclusive):

1. Runtime gate in the skill pattern: Step 3 should verify REVIEW_COMPLETED=true was set by Step 2 within the current pr-codex-bot invocation, not just check if any prior review exists
2. PATTERN.md warning: Add explicit "FORBIDDEN: pushing before Step 2 completes" to the pattern
3. Orchestrator guardrail: The skill could check git log origin/main..origin/${WORKFLOW_BRANCH} to detect if the branch was already pushed and warn/abort if review hasn't run yet

Context

• Skill: pr-codex-bot (SKILL.md + patterns/pr-codex-bot/PATTERN.md)
• The push-before-review happened because the orchestrator treated push as a prerequisite for the skill invocation rather than as part of the skill's managed workflow

[RyderFreeman4Logos]

Fixed in PR #390 (v0.1.110).

Assessment: The bash-level enforcement (Step 4 checks REVIEW_COMPLETED=true) was already present, but the orchestrator could push the branch before invoking the skill.

Fix:

• Runtime detection: Step 4 now checks git ls-remote for the branch before pushing. If found, emits a warning that unreviewed code may have been visible to CI/reviewers
• Force-with-lease push: Changed from git push to git push --force-with-lease so the reviewed code always overwrites any pre-pushed version
• Documentation: Added explicit FORBIDDEN prerequisite in SKILL.md about pushing before invoking the skill

Not changed: No system-level runtime gate was added (would require changes to the weave compiler's condition/precondition system). The enforcement remains at the bash/documentation level, consistent with the existing pattern architecture.