listTeams() deep-cloned ALL team summaries via structuredClone on every call -- even
cache hits and concurrent in-flight awaiters. A heap allocation sample of a launch
put this (listTeams -> cloneTeamSummaries -> structuredClone) as the single largest
memory allocator, driving heap churn + GC pressure during launch (this stand has ~158
teams, and listTeams is called constantly: startup, notification init, task projection,
IPC polls, provisioning).
Build ONE deep-frozen, independent snapshot per uncached load and hand the same
reference to the cache entry, in-flight awaiters, and every later reader. The single
cloneTeamSummaries keeps it independent of any cached config the loader returns;
freezing lets all readers share it safely. Audited every listTeams consumer -- all
iterate / map / filter / serialize, none mutate -- and the freeze turns any stray
future mutation into a loud error rather than silent cross-caller corruption.
TeamConfigReader 26/26 (added a frozen + same-reference regression test), and the
listTeams consumers (TeamDataService 116, CrossTeamService 26) all pass under frozen
summaries.
