Two credential-isolation gaps found in review of the previous head.
1. strip_launch_profile_env() only knows dotenv- and terminal-config-owned names,
but external secret sources (vault, 1Password, ...) also write their names into
the shared os.environ and are tracked in secret_source_names(). A name the LAUNCH
profile's source supplied therefore still reached a routed no_agent child. Drop
every non-global source-owned name from the base; the routed scope overlay that
follows puts back exactly the ones that profile's OWN sources supply, since
build_profile_secret_scope folds get_secret_source_values(home) in.
2. refresh_installed_secret_scope() merged the rebuild with dict.update(), so a
name a source had stopped supplying -- rotated, revoked, source removed -- kept
its old value for the rest of the fire. Replace the mapping contents instead: the
rebuild is the profile's current truth.
Regressions: a routed child sees <unset> for a launch-source name while its own
source value comes through, and a refresh whose rebuild omits a name drops it.
Both fail if the corresponding change is reverted.
(cherry picked from commit ecd51517c4828a75acb5f458ed99aea0bc3e5e9f)
John Paul Soliva
0943e77136