[Studio][Bug] About tab shows stale hard-coded build metadata

## Problem The RocketMQ Studio Settings > About tab displays hard-coded build metadata: - version: 0.1.0 - build time: 2024-01-15 14:30:00 Those values remain unchanged across later builds, so operators cannot identify which frontend artifact is actually deployed while diagnosing a control-plane issue. ## Expected behavior - The displayed Studio version comes from the frontend package metadata. - The displayed build time is generated for the current frontend build. - Development and production builds both render non-empty values. - The values are covered by a focused page test. ## Scope Track 1 / control-plane operability. Frontend build metadata and the Settings About tab only; no AI/LLM behavior.