Improve CLI run UI and preflight startup check

[ykykj]

Summary

• Refresh CLI welcome/settings/result UI with clearer panels and live run dashboard
• Keep interactive input on the existing main-branch PromptSession flow
• Avoid importing akshare during preflight by using importlib discovery

Tests

• python -m pytest agent/tests/test_preflight.py agent/tests/test_cli_init.py agent/tests/test_llm.py
• git diff --cached --check

[warren618]

Thanks for the CLI polish. The refreshed run UI and startup preflight check should make the first-run experience smoother without touching the protected agent core. Merged.