[ docs ] document WebUI client

[flynntsang]

User Story

• As a web designer
• I want to use the Eidolon React components
• So that I can:
  • integrate AI agents into my web site or SaaS application
  • build a stand-alone web UI dedicated to agentic applications (similar to our WebUI)

Acceptance Criteria

• Given that I am browsing the Eidolon documentation
• When I see a heading named "Clients"
• Then there is a subheading for "React Web Components" that includes pages on where to find React components, what they do, and how to configure them.

Background It's not clear how you use webui.apps.json and the resources YAML files to enrich the user experience.

For example, how do you extend input_schema (e.g., to include first_name), modify the user_prompt, and display certain inputs in the webui.

[LukeLalor]

• [ ] audit exposed components (do we want / need to expose them all? are there missing components?)
• [ ] audit api on exposed components (do they need refactor)
• [ ] Create styling plan for docs (ie, css customization rules)
• [ ] nextjs template app
• [ ] Example with custom template used
• [ ] docs on all above