* fix: pin plugin workspace dir for sessions.list to avoid O(rows) memo busting
sessions.list was O(rows) slow under concurrent agent/cron load because
each row read a process-global active plugin-registry workspace dir
that was mutated by other turns between rows. The per-row memo key
changed every time, so loadPluginMetadataSnapshot scanned fresh
(~100ms per row).
Fix:
1. Add AsyncLocalStorage-based workspace dir pinning to
runtime-workspace-state.ts — withPinnedActivePluginRegistryWorkspaceDir()
snapshots the current workspace dir for the duration of a callback.
2. Wrap listSessionsFromStoreAsync body in the pin so all per-row
metadata lookups use a stable memo key.
Fixes#90814
* test(plugins): cover request-scoped workspace pins
* fix(plugins): pin canonical runtime workspace reads
* fix(plugins): preserve workspace pins across reloads
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Co-authored-by: lsr911 <lsr911@github.com>
Co-authored-by: Vincent Koc <25068+vincentkoc@users.noreply.github.com>
