Add monitor-account-pool to select authorized, non-blocked candidates
for an AI-platform monitor task, classify failover reasons (risk
control, challenge, auth failure, empty/unknown result) and cool the
account down before rotating to the next. Wire runtime-controller to run
monitor tasks through the pool, retrying across accounts and annotating
the result with per-account attempt diagnostics and a failover count.
Expose the pool state via the runtime snapshot.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
