- Remove hardcoded OPENROUTER_MODEL_CHOICES from openrouter.py
- Add API endpoint /integrations/openrouter/models/ to fetch models dynamically
- Models loaded from OpenRouter API with free models (':free') at top
- Update OpenRouterIntegration model_name field (remove choices, blank=True)
- Add async buildForm() with dynamic_choices support
- Show asterisks (********) for saved API keys with helpful placeholder
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>