Add Elicitation / Structured Input UI

[PureWeen]

Summary

When the agent needs specific structured input (e.g., "Pick a framework", "Choose options"), the CLI renders structured forms via the Elicitation API. PolyPilot falls back to plain text input.

SDK API

• SessionConfig.OnElicitationRequest → ElicitationHandler callback (v0.2.1)
• session.Rpc.Ui.ElicitationAsync(message, schema) — request structured input
• Events: ElicitationRequestedEvent (includes RequestedSchema), ElicitationCompletedEvent (includes Action, Content)

Proposed Implementation

1. Dynamic form rendering when elicitation is requested:
   • Dropdown/select for choice lists
   • Checkboxes for multi-select
   • Text fields with validation
   • Radio buttons for single-select
2. Schema-driven UI — render based on the RequestedSchema from the event
3. Inline rendering in the chat flow (like a card/modal within the conversation)
4. Fallback to text input if schema can't be rendered

Value

Much better UX than "Type 1, 2, or 3" in a text box. Makes agent interactions feel native and polished.

Priority: 🟡 MEDIUM