SQLite json_extract coerces JSON false/true to integers 0/1 (absent key returns NULL)

Writing a SQLite migration or query that branches on a boolean stored inside a JSON text column (e.g. attrs_json = '{"provisional":false}'). It's easy to assume json_extract(attrs_json, '$.provisional') returns the string 'false'/'true' or a SQL boolean, and write a predicate that silently never matches — mis-bucketing rows during a one-shot data migration.