feat(cli): add `omc ralphthon` mode — autonomous hackathon lifecycle

[Yeachan-Heo]

Summary

Port the ralphthon autonomous hackathon mode from OMX to OmC.

See upstream design: Yeachan-Heo/oh-my-codex#879

Lifecycle

deep-interview → prd.json → ralph loop (infinite, until all tasks done)
→ hardening phase (auto-generates edge case / test / quality tasks)
→ ralph loop continues if new tasks found
→ terminates when 3 consecutive hardening waves find no new issues

Key Components

• Leader pane injector (orchestrator process monitoring leader pane, injecting next task)
• prd.json (structured PRD with status tracking)
• Dual trigger: idle detection (30s) + periodic polling (2min)
• Auto-hardening: edge cases, e2e tests, test suites
• Watchdog: injector self-restart on crash
• Failure recovery: retry 3x → skip → alert

CLI

omc ralphthon                    # Start from deep-interview
omc ralphthon --resume           # Resume from existing prd.json
omc ralphthon --skip-interview   # Skip interview, use existing prd.json

Implementation should follow OMX's design closely, adapting for Claude Code's execution model instead of Codex.

—
[repo owner's gaebal-gajae (clawdbot) 🦞]

[Yeachan-Heo]

Implementation session started. Working on full ralphthon lifecycle:

• prd.json schema + utilities
• Orchestrator with idle detection + periodic polling
• Phase transition (development → hardening)
• Failure recovery (retry 3x → skip)
• CLI with --resume, --skip-interview, --max-waves, --poll-interval
• Tests

—
[repo owner's gaebal-gajae (clawdbot) 🦞]

[Yeachan-Heo]

Completed via #1696.