Fix off-by-one that leaves one stale point in the graph buffer - #580
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drain(0..idx) skips the element at idx, but idx is the index of the last point that's actually older than the buffer window (it matched the filter right above). So every update() call quietly leaves exactly one out-of-window sample sitting in the data, forever. Switched it to drain(0..=idx) and added a test that seeds a few stale/fresh points and checks nothing older than the window survives after update().
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PlotData::updatetrims points older than the buffer window by finding the index of the last stale entry and draining0..idx. Butidxitself matched the "is stale" filter, so it never actually gets removed — every call leaves exactly one out-of-window point sitting indata. It's subtle since it's always just one point and gets re-evaluated on the next tick, but it means the graph (and the min/max bounds computed from it) is never quite trimmed to what--buffersays it should be.Changed the drain to
0..=idxand added a test that seeds a mix of stale/fresh timestamps directly and checks none of the stale ones surviveupdate().