Task: Integrate Chat UIKit to build a WeChat-style chat app (full-featured mode, minimal runnable setup).

Instructions:
1. Detect the framework automatically (React / Vue3 / Flutter / Android / iOS).
2. If the framework cannot be determined, call `present_framework_choice` so the user can choose.
3. Call the appropriate MCP tool by platform:
   - Web: `get_web_chat_uikit_integration`
   - Native: `get_native_chat_uikit_integration`
4. Parameters:
   - `framework`: use the actual framework (e.g. react, vue, flutter, android, ios).
   - `goals`: `['full-featured']`
5. Call `get_usersig` to obtain credentials for two test user IDs, then wire up SDK init and login.
6. Generate the full chat entry (conversation list + chat window + contacts/profile) and a login page where users can pick a test account. Register routes or pages as needed.
7. Start the project and report: files changed, run command, and how to verify.

Acceptance checklist:
- SDK initializes successfully
- User logs in successfully
- Conversation list is visible
- Messages can be sent and received

Troubleshooting:
- Invalid userSig → call `get_usersig` again
- Login failure → check `SDKAPPID` / `SECRETKEY` (or equivalent) env vars
- Messages not showing → check conversation ID format (e.g. `C2Cuserxxx`)

Constraints:
- Do not use deprecated APIs.
- In production, UserSig must be issued by your backend, not the client.