fix(studio): stabilize agent detail refresh and debug runs

[richarddancin]

Summary

• refresh Studio agent metadata after same-runtime updates so graph/detail state does not stay on the old version
• make agent detail version display use one current-version source so header and detail fields stay consistent after updates
• prevent stale generated-agent debug runs from consuming the 3-panel quota, and scope backend debug-run quota by owner
• add regression checks and rebuild the bundled Studio web assets

Context

Built on top of #766 because these bugs reproduce in the agent catalog/detail workflow. Rebasing onto current main pulled in the latest feedback-case/agent-management work.

Verification

• cd frontend && npm test
• cd frontend && npm run build
• uv run pytest tests/cli/test_generated_agent_backend_codegen_extended.py -k owner_scoped
• uv run veadk studio update --vefaas-app-name veadk-studio-pr766-fix --region cn-beijing --project default
• manually verified the updated Studio at https://snqb41t7i90keu364e644.apigateway-cn-beijing.volceapi.com