Wave 4 hardening. Wrap untrusted CV/job-description/instruction text
in tools/summarizer prompts with explicit delimiters and an
ignore-embedded-instructions rule, since JD text, recruiter emails,
and free-text candidate background all flow into rewrite/normalize
prompts unescaped today.
Match score previously normalized synonyms (JS/Kubernetes/K8s/etc)
only when scanning the job posting, not when checking the CV corpus,
so a CV using an abbreviation the job spelled out never matched.
SkillTagger.MatchesTag reuses the same synonym regex for both sides.
The structured /cv/* calls funnel through a provider router so production can
offload a weak local GPU (GTX 1060) to a cloud provider without any .NET change.
Default stays "ollama" (keyless/local) and /summarize remains local distilbart.
- AI_PROVIDER=ollama|gemini|groq dispatch inside _ollama_generate_json/_text
(entry-point names kept, so no call sites change; Ollama path is byte-identical).
- Gemini (x-goog-api-key header, not URL query) and Groq (OpenAI-compatible
chat/completions) added via stdlib urllib — zero new dependencies.
- /health reports ai_provider + ai_provider_configured.
- Keys read from env only; never logged/committed.
- Compose + .env.example pass AI_PROVIDER/GEMINI_*/GROQ_* through.
Tests: 11 passed (default Ollama unchanged, Gemini/Groq dispatch, missing-key 503,
health reports provider).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>