fix(ci): verbose logging + hardcode REPO + better PR fallback

[jimmy-claw]

Key fixes for the LEZ bump workflow:

• Hardcode REPO env var so gh CLI always targets the correct repo
• Much more verbose logging at each step (dumps all gh output)
• Better fallback chain: gh pr create → gh pr list → skip
• Separate pr_result step that outputs pr_number to GITHUB_OUTPUT
• Proper handling of exit 4 (PR already exists)

Note: workflow_dispatch from fork PR context has limited permissions. Scheduled runs (cron) work fine — this is for diagnostics and robustness.