- Add agent generation service with OpenAI/Anthropic support, streaming, and error handling
- Add POST /agent/generate API endpoint with SSE streaming and cost tracking
- Add API client functions for agent generation with AbortController support
- Create AgentGenerationModal component with live preview, streaming, and import flow
- Integrate AI Generate button into NewAgentDialog with configuration options
- Add comprehensive unit tests for service and component
- Add changeset for @gsxdsm/fusion minor bump
- Replace plain text input for model selection with CustomModelDropdown component in NewAgentDialog
- Add provider/model selection with grouped dropdown UI and search filtering
- Support editing existing agents with pre-populated model values
- Add comprehensive test suite (374 lines) covering rendering, interaction, and edge cases
- Wire up agent creation and editing flows to use the new dropdown for model selection