Salvages the substantive part of #22295 by @steezkelly. Adds the
missing HERMES_KANBAN_HOME, HERMES_KANBAN_RUN_ID, HERMES_KANBAN_CLAIM_LOCK,
HERMES_KANBAN_DISPATCH_IN_GATEWAY entries to _HERMES_BEHAVIORAL_VARS so
ambient developer-shell pins on those vars don't bleed into pytest runs.
The frozenset extraction + standalone regression test from the original
PR were dropped to keep the change minimal — main already maintains the
list inline.
steezkelly
d3345cc70d