987064caa4
The PR narrowed _is_fts_write_corruption_error to only match FTS5-specific 'fts5: corrupt structure record' errors, dropping the generic 'database disk image is malformed' match. But FTS shadow table corruption (the common case) raises the generic error on SQLite < 3.53, not the FTS5-specific one. This broke FTS self-heal for 10 existing tests and for users on older SQLite. Restore the generic match via is_malformed_db_error. Safety is preserved because the FTS rebuild only touches derived indexes — if the damage is actually in a canonical B-tree, the rebuild itself fails and the write propagates. Also restore the original test assertion and remove the test_generic_malformed_write_fails_closed test whose premise (generic corruption should not trigger FTS rebuild) was wrong for the FTS self-heal path.