Select component documented but not exported in v0.2.1-beta

[christoph2806]

Issue Description

The Select component is documented in the agent guide and usage recommendations, but it's not actually exported from the @etherisc/ui-kit package in version 0.2.1-beta.

Expected Behavior

Based on the documentation in docs/development/tools/ai-development/agent-guide.md, the Select component should be importable:

import { Select } from '@etherisc/ui-kit';

<Select
  label="Country"
  placeholder="Select a country"
  options={[
    { value: "us", label: "United States" },
    { value: "ca", label: "Canada" },
    { value: "uk", label: "United Kingdom" },
  ]}
  value={country}
  onValueChange={setCountry}
/>

Actual Behavior

TypeScript error: Module '@etherisc/ui-kit' has no exported member 'Select'.

Environment

• Package version: @etherisc/ui-kit@0.2.1-beta
• TypeScript project

Additional Context

The package.json shows @radix-ui/react-select@^2.2.4 as a dependency, suggesting the Select component infrastructure is there, but it's not being exported from the main index.

This is blocking the implementation of organization management forms that need dropdown selection functionality.