create --type bugfix
new spt-hosted session bringup wedged after daemon/broker cold restart (harness-hosted unaffected)
Observed on HFENDULEAM 2026-07-29 after the 02:25 daemon+brain cold restart (generation 0): every NEW spt-hosted session failed bringup while all pre-existing live agents kept working and harness-hosted sessions started fine.

Evidence (daemon.stderr.log):
- New-session controller attaches die instantly: controller-attach -> write-start -> writer-exit reason=channel-closed -> transport-close within ~100ms (chert sessions 10/11, slate session 12).
- Anonymous role=brain connections (no endpoint/session attribution) opening on a ~5s supervisor cadence and closing within 0-6ms of write-start, dozens over minutes (conn 1175..1199+) — bringup retry loop dying before identification.
- Roster/daemon state divergence in the same window: subnet roster showed chert ONLINE while daemon status said ready=false alive=false; daemon listed an endpoint the roster did not.
- HOSTING_AUTHORITY_DEMOTED:chert: no broker session, but a relay holds the endpoint.

Confounder to exclude in RCA: a Claude session limit was ALSO active in the window (limit banner verbatim in log, exit 1) and explains some early chert attempts — but a later launch via an unlimited profile still failed bringup, so the wedge is real and broker-side. Fleet is on v0.45.0.
Operator impact: cannot grow the fleet until daemon bounce; existing agents ride pre-established hosting and mask the defect.