weichenandCursor
b6d57b9f8e
Add B5 load seed tool and C2 dual-instance load entry
Why: U7 release checklist B5/C2 needed volume seed and dual-serve load wiring before capacity windows.
Evidence: tiny single/dual smoke (skip-k6) SSE p95≈4ms, dup_seq=0; seed COPY 1k msgs/chunks in ~30ms.
Impact: run_load.sh --seed/--instances; docs/release-multi-instance B5/C2 → ready; no backend product change.
Refs: docs/proposals/2026-10-11-collaboration-storage-and-distribution.md §3/§5 U7; docs/release-multi-instance.md
Co-authored-by: Cursor <cursoragent@cursor.com>