New default dashboard card

[Caesarh97]

We already have over 800 displayed sites and only 39 deployed buoys. Once we have the Reef Check sites available, there will be even more sites without a buoy connected to them. Because of this, it would be great if we changed the "Buoy Observation" dashboard card.

When a site does not have a buoy, the default mode should be a new dashboard card instead of “Buoy Observation”. The new card should show the change in temperature over the past 7 days compared to the 7 days before that. It should show the increase / decrease in absolute terms (e.g. +1C, the previous temperature e.g. 27c and an arrow up or down - blue if colder, red if hotter). This would come from SST and would only be shown if we have no spotter.

Below are 3 examples of how the dashboard could look like. Note that I included two images for each example. We could also consider displaying the 7-day average temperature at the bottom, as it forms the basis for the calculated change. Please let me know what you think would be best.

UPDATE: We should do Example 2.

Example 1

Example 1

Example 2

Example 2

Example 3

Example 3