Hooks with exit code 2 were silently failing to block.

Documented behavior says a hook exiting 2 blocks the tool call. In practice, if the hook's stdout JSON failed schema validation, the block got dropped and the tool ran anyway. Fixed in v2.1.214, alongside the v2.1.212 fix for continue:false halts being dropped when a tool failed or completed mid-stream. Across two releases, four separate fixes address guardrails that reported blocking but didn't. Harnesses reliably surface a hook's happy path and silently degrade its failure path. Treat any hook you use as a safety control as untested until you've verified it blocks under a malformed payload, a mid-stream tool failure, and a non-zero infrastructure error.