[codex] Keep shared task home return visible

[anarkh]

Summary

• Keep the share demo task post_001 fresh for 30 days and refresh old local-storage copies before they expire.
• Move 回首页查这条 out of the active-only receiver action strip so expired share pages can still return to the homepage focused on the shared task.
• Extend share receiver and performance guards to cover the long-lived fixture and expired-share home-return behavior.

Validation

• bash harness/init.sh
• node scripts/check-share-receiver.mjs
• node scripts/check-share-receiver-action.mjs
• node --no-warnings scripts/check-performance-guards.mjs
• node --no-warnings scripts/check-devtools-readiness.mjs
• git diff --check HEAD~1..HEAD

Notes

• Existing DevTools service-port smoke remains blocked by local port 9420 configuration, as reported by readiness; this PR does not claim real-device or DevTools UI passed evidence.