[Juliusolsson05]

Summary

• remove the Event-Driven Paste Submit setting from settings type, persistence, and UI
• make Claude paste-like submits always use placeholder-based event-driven detection
• keep the 125 ms timer only as an internal fallback when placeholder detection cannot run or times out
• update paste comments/debug logging to reflect that this is mandatory behavior, not a user toggle

Why

The 125 ms wall-clock path has never been reliable under real Claude paste accumulator behavior. Users should not be able to disable the regex/placeholder wait path; it is the correct protocol.

Verification

• npm run test:settings-coerce
• npm run build