.env is data; .envrc is executable shell that direnv runs on every cd, so
copying it into a worker moves behaviour, not just values. The default
parityOverlay is now [.env] only. The knob is unchanged: an operator who
wants .envrc copied can still write parityOverlay: [.env, .envrc]
explicitly.
Updates FleetConfig's default and javadoc, fleetd.example.yaml's two
mentions of the default, and the FleetConfigTest coverage: renamed the
default test, added parityOverlayExplicitEnvrcOptInStillWorks to prove
the .envrc opt-in escape hatch still works, and fixed
WorktreeSessionManagerTest#worktreeAcquireRunsParityOverlayWithProfileDefaults
which also hardcoded the old default.
Dai Ha
8bba3a8184