Harden the Anthropic provider and lay the groundwork for schema-constrained
JSON, optimizing the existing claude-sonnet-4-6 / claude-haiku-4-5 usage
(no model changes).
ai_provider.py:
- _extract_text_from_response replaces fragile response.content[0].text:
skips non-text leading blocks (e.g. thinking), returns the first text
block, logs an anthropic.stop_reason warning on max_tokens/refusal
(truncation now observable), and raises ValueError on a no-text response.
- generate_json gains an optional `schema` param. Anthropic wires it to
output_config.format (structured outputs); schema=None preserves the exact
prior call for every existing caller. Gemini accepts-and-ignores it.
kb_conversion_service.py:
- TROUBLESHOOTING_SCHEMA / PROCEDURAL_SCHEMA + _schema_for_target_type(),
modelled as a strict superset of every field the prompts emit.
- convert_document passes the schema only when the new
AI_KB_CONVERT_STRUCTURED_OUTPUT setting is True (default False). The
_try_repair_json fallback stays as belt-and-suspenders.
Tests: 14 provider + 7 schema, TDD (red-green). Live constrained-decoding
smoke-test still required before enabling the flag in production.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
