Extends the regex-only pre-check into three stages: regex scan, then
embedding-similarity search against known injection examples, and only
if that score clears a threshold, an LLM judge confirms intent before
blocking. Catches paraphrased injection attempts the fixed regex
patterns miss without paying for an LLM call on every query.
Validated end-to-end against a real Anthropic API key and a live
Qdrant instance: the new path correctly blocked a paraphrased
injection (audit log confirms rule_id: injection.semantic_llm_judge)
while a benign near-miss passed through without ever reaching the LLM
judge. Also documents two reliability issues found while testing with
claude-haiku-4-5 (a non-deterministic policy verdict and a forced
tool-call loop that can end without calling any tool) in
docs/SAFETY_WRITEUP.md section 6 -- unrelated to this change, but
worth recording since they were found in the same pass.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
