drawWindRose used canvas.width (physical pixels) for coordinates while
the context was already pre-scaled by devicePixelRatio. On iPhones
(dpr=2/3) this placed the entire rose off-screen. Fix by dividing by
dpr to get CSS dimensions before computing cx/cy/R.
Also make sWindDir stat always show a value ('—' fallback when winddir
is null) and add null guards on sEventRainTile/sTotalRainTile to
prevent a silent throw from aborting updateLatest() early.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Nate EmmertandClaude Sonnet 4.6
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