777a7700b4
Opens one v8 Event session and measures SendEvent reuse (register-once, send-many) + best-effort read-after-send + optional idle sweep. Skips offline; run live in B0c to gate event amortization (pending.md A1 broadening, Stage B0). Claude-Session: https://claude.ai/code/session_012SDSQ3AcaXqPcBtDESBRii