[vaprdev]

Summary

Every plant rocked on its own sine wave, so scenes never felt like they had weather. A shared wind in src/wind.ts sends a gust across the whole screen, left to right, every minute or so.

+gust(x, t)          0..1 at x; add to petals, snow, dust
-Math.sin(t * rate + phase)
+sway(x, t, phase, rate)   same rocking in calm air, plus a lean as a gust passes
+SwayLayer           bends plants painted once in layout() without redrawing them

Used in every outdoor scene, with mist, heat shimmer and flags that respond to it; ocean motes light up in the light shafts. Exported from the API and documented.

Evidence

Before (main) on the left, after on the right.

A gust crossing the farm

Verification: bun run typecheck passes; CI's check job runs dev/check.ts (flicker, frame time) on this branch.

Merge Danger

Door: two-way

Blast Radius: visuals

All outdoor wallpapers; gust lean is softened during integration in #1.

Merged together with the other visual improvements in #1; this PR's CI screenshot check fails by design because screenshots are regenerated there.