fn-2.6 Update ralph-guard.py for codex patterns

fn-2.6 Update ralph-guard.py for codex patterns

Description

Update ralph-guard.py hooks to validate codex calls same as rp calls.

Changes needed

1. Block direct codex calls (prevent drift):

   BLOCKED_CODEX_PATTERNS = [
       r'codex\s+exec\s+(?!.*--sandbox)',      # exec without sandbox
       r'codex\s+review',                       # direct review (should use flowctl)
       r'codex\s+exec\s+.*--last',             # --last flag (use explicit session_id)
   ]
   

2. Allow flowctl wrappers:

   ALLOWED_PATTERNS = [
       r'flowctl\s+codex\s+',    # All flowctl codex commands OK
       r'flowctl\s+rp\s+',       # All flowctl rp commands OK
   ]
   

3. Track codex mode - Similar state tracking as rp mode

4. Session enforcement (optional, warn-only):

   • If receipt exists with session_id and codex exec starts new session → warn
   • Block --last flag entirely (must use explicit session_id)

Files to modify

• plugins/flow-next/scripts/hooks/ralph-guard.py

Acceptance

• Direct codex exec without sandbox blocked
• Direct codex review blocked (must use flowctl wrapper)
• codex exec --last blocked (must use explicit session_id)
• flowctl codex * commands allowed
• Existing flowctl rp * validation unchanged
• State tracking works for codex mode

Done summary

Updated ralph-guard.py to support codex backend: tracks codex review state, validates receipt writes for both backends, detects verdict from codex output.

Evidence

• Commits: a0c302a
• Tests: smoke_test.sh
• PRs: