Alternative that drops the in-place rebuild machinery (buildReplacement, swap,
recoverMigration, verifyMigrated, the fixup hook) and just wipes the outdated
bleve index so a full 'search index --force-rescan' repopulates it. ~272 lines
lighter, but trades the fast no-rescan migration for a Tika re-crawl on every
schema bump. Kept in history for reference; reverted in the next commit - the
in-place migration is worth the ~300 lines for bleve too.
4788a98cdc