finalizeExpeditionOnZoneClear and its wiring into the run-complete seam
were introduced in 73b7809 but that commit never made it into the
current history — it's not an ancestor of HEAD, so the function, its
call site in advanceOnceWithOpts, and its tests were all absent.
Symptom: clearing a zone (boss down, no outgoing edges) set the run's
boss_defeated flag but never flipped the wrapping expedition to
'complete' or retired the run. The expedition sat 'active' pointing at a
boss_defeated run, so getActiveZoneRun (filters boss_defeated=0) returned
nil and the next '!expedition run' errored with 'No active zone run'. The
ambient ticker also kept DMing about a finished dungeon.
Re-apply the bridge verbatim against current HEAD (deps verified present:
IsMultiRegionZone / CurrentRegion / MarkRegionBossDefeated /
completeExpedition / retireAllRegionRuns / AwardCompletionMilestones) and
restore the test.
