The relocated '# Environment' block put model-identity/catalog lines in
the LAST user message every turn, steering subagent picks to fable
instead of haiku (LinkedIn report). splitEnvByVolatility now learns per
project (claudeMdSha) which env entries are byte-stable and promotes
them into the imaged slab; churned/new entries keep the live-tail
relocation, with the identity regex retained as a second layer.
Invariants (pinned by tests):
- first-ever sightings stay volatile: git state never bakes into a
fresh session's image (48.8% cold-create fix intact)
- the slab never re-renders mid-session: static side frozen byte-exact;
a churned promoted entry re-emits fresh text on the tail (supersedes
its stale slab copy) and demotes next session via sticky churn history
- no user message -> env stays in system, unchanged
Telemetry: envStaticChars / envVolatileKeys.
teamchong