Adds generative-ui, frontend-tools, shared-state, and human-in-the-loop
sections to the DeepAgents integration docs by porting from the LangGraph
integration (same underlying mechanism). Also updates the integration
feature generator script to include deepagents and regenerates
integration-features.ts so DeepAgents appears in per-feature grids.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>