GET /github/installations strips the numeric installation_id for non-admin
members, but the github_installation:created / uninstall / suspend WS
events were still publishing it, so the same handle was reachable from
any workspace client subscribed to the workspace scope. Broadcast both
payload variants without it — the frontend uses these events only to
invalidate the installations query, so admins re-query the list endpoint
to recover the management handle.
Also adds a router-level test that mounts the production middleware split
(member-visible list vs. owner/admin connect+delete) so a future routing
change can't silently widen the write surface.
Co-authored-by: multica-agent <github@multica.ai>
723c5cb459