A DB<->filesystem path mismatch (Docker volume change, remount, Music
Paths unset for the container) makes EVERY library file fail to resolve
to a DB track, so the orphan detector flags the whole library as
orphaned. The mass-orphan check only logged a warning and then created
the findings anyway — so a user batch-applying 'move to staging' or
'delete' would relocate or wipe their entire library.
Make it a hard skip (create zero findings) like the dead-file cleaner
and stale-removal paths already do (#828). Centralise the predicate as
is_implausible_orphan_flood() alongside is_implausible_stale_removal()
so the rule lives in one tested place. Small genuine orphan sets still
surface unchanged — only an implausibly large flood (>50% and >20) is
suppressed.
Tests: seam cases for the new predicate + scan-level regressions (mass
mismatch -> 0 findings; small genuine set -> still reported).