feat(studio): add runtime live log viewer

[evanlowe]

Summary

• add a Studio BFF endpoint that resolves the active VeFaaS instance and streams logs without changing Runtime APIs
• add a realtime log dialog beside the conversation disclaimer, including instance console links and ANSI-colored output
• support both Volcengine and BytePlus in locally served and cloud-deployed Studio environments
• package the rebuilt Studio WebUI assets

Validation

• npm run build
• npm test (879 passed)
• npm run test:webui-assets
• npx tsc --noEmit
• uv run pytest tests/frontend/server/test_runtime_logs.py tests/frontend/server/studio_tools/test_connector.py tests/cli/test_frontend_runtime_proxy.py -q (64 passed)
• uv run pre-commit run
• Playwright visual checks at 1440x900, 390x844, and 844x390
• live verification against Volcengine and BytePlus runtimes