Dashboard minor issues after the Vite upgrade

[jeesunikim]

1. Redis cache race condition - The "Txs & Ops in the last 30 days" chart shows infinite loading because the server starts accepting requests before the cache is populated.
2. Missing error handling - All chart components make axios calls without .catch() handlers, causing silent failures when rate limits or network errors occur.
3. Interval cleanup missing - Several components use setInterval without cleanup in componentWillUnmount, which will cause issues with React 18 StrictMode.
4. We should also modernize the old react pattern to the latest (componendDidMount to useEffect)
5. [non critical] Unnecessary .jsx extensions - 31 import statements have .jsx extensions (old code didn't have these). Low priority since it works fine.

Reference: #345