Live chain status dot proposed for Satsuma's three public sites

Three pull requests were opened, one each in satsuma-website, satsuma-explorer and satsuma-engineering, adding a small live dot next to a Status link in each site's footer. The dot shows the health of Satsuma's chain, read from Satsuma's status page. None of the three are merged or deployed; all three await review.

Each site asks the status page once when the page loads, then every 60 s while the tab is visible. It reads only one field, the state, and a 503 response reporting down turns the dot red. If the request fails or the answer is not what was expected, no dot is shown at all rather than an error. Pages that the browser prerenders in the background wait until they are actually opened before asking.

The dot's colours come from each site's own colour variables; amber and red were added to the website and engineering themes. The explorer and the engineering site had no Status link in their footers, so one was added alongside the dot.

The changes sit on a branch in each repository and wait for review before anything is merged or deployed.