- Add output_language config key to DEFAULT_CONFIG (default: English)
- Add get_language_instruction() helper to agent_utils.py
- Inject language instruction into 4 analyst agents and portfolio manager
- Internal debate chain (Bull/Bear/Risk debaters) stays in English to preserve reasoning quality and BM25 memory compatibility
- Fix OpenAI-compatible providers with custom base_url incorrectly using Responses API instead of Chat Completions