Dashboard API Timeouts, Tries and Intervals

When a user is in their dashboard there should be logic that populates their DOM with some kind of persistent data that wont change about their portfolio: crypto name, icon, the bootstrap element the data lives in etc.

API calls should be made in 1 minute intervals for price data and 5 minute intervals for candle updates. And the user shouldn't have to lose all their DOM elements if the API hits a 429 error.

-loading gifs and opacity layer should populate if the user is waiting for an API call
-if a call gets a 429 error: try-catch logic should set a wait interval to request again in 20second - 1 minute intervals

该 issue 没有指定文件、测试或入口点。首先定位 dashboard DOM 填充和 API 请求的入口点，然后跟踪价格和蜡烛更新是如何调度的，以及错误会如何影响现有元素。完成的标准是：持久化的投资组合数据保持可见，更新使用所述的时间间隔，请求期间显示加载状态，并且 429 响应会触发重试而不会清空 DOM。

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