The model-run maintenance fields (modelRunPruneAfterMs from #88632 base work,
modelRunPruneAfterConfigured from the pressure-gating fix) were required on the
resolved maintenance config exposed to plugins via patchSessionEntry's
maintenanceConfig. External plugin TypeScript callers that construct a
pre-#88632 maintenanceConfig would fail to compile.
Make both fields optional on ResolvedSessionMaintenanceConfig (and the runtime
type), so old-shape plugin configs keep compiling. All internal readers already
treat an absent value as unset: shouldRunModelRunPrune returns false when
modelRunPruneAfterMs == null and modelRunPruneAfterConfigured is falsy, so a
plugin-supplied config without the fields runs no model-run pruning — the
pre-#88632 behavior. The resolver still always populates both fields, so normal
runtime behavior is unchanged. Add an old-shape maintenanceConfig SDK
regression test.
Forced maintenance (sessions cleanup / maintenanceOverride) caps immediately to
maxEntries, but the unset model-run default was high-water gated. In the
(maxEntries, high-water) window stale model-run probes survived while the forced
cap evicted real sessions — the inverse of #88632. shouldRunModelRunPrune now
takes a force flag: when the caller caps immediately, the unset default prunes
once entryCount > maxEntries. Wire force at the two forced call sites
(applyEnforcedMaintenance, previewStoreCleanup). Make the SDK runtime config
field modelRunPruneAfterConfigured optional (additive). Add force-gate unit
test + forced-apply regression test.
The model-run prune predicate fell back to testing the raw sessionKey
when parseAgentSessionKey returned null, so unscoped keys like
`explicit:model-run-<uuid>` and shapes with empty agent ids were
eligible for the new default 24h cleanup. Restrict matching to keys
that successfully parse as agent-scoped with a non-empty agent id,
and add negative tests covering unscoped, empty-agent, extra-segment,
and whitespace-padded keys.
Refs #88632 (review feedback before merge).
