[codex] add copse auto update flow

[getsolaris]

Summary

• add shared GitHub Releases update checking, cache/throttle state, install-method detection, and update execution planning
• add explicit copse update plus opt-in CLI launch and TUI update prompts
• document update config and no silent update/daemon/telemetry behavior in README, Korean README, examples, and skill smoke refs

Notes

• launch/TUI prompts require updates.enabled: true; explicit copse update works regardless
• production code does not ship COPSE_UPDATE_TEST_* hooks

Verification

• bun run typecheck
• bun test (393 pass / 0 fail)
• bun run build
• tmux CLI/TUI QA for explicit update, launch prompt, and TUI modal
• final ulw-loop gate: G001-G008 complete, 24/24 criteria pass