feat(wind): add keyless NOAA GFS wind layer with animated particles

Add a Wind layer animating the global 10 m wind field from NOAA GFS.

The /api/wind proxy selects the latest available 0.25° cycle, reads its .idx
inventory, byte-range fetches only the UGRD/VGRD 10 m GRIB2 messages (~1 MB
each instead of the whole ~500 MB file), decodes them with ecCodes (WASM),
resamples to a compact grid (1° default), and serves a manifest plus a Float32
U/V payload cached per cycle for an hour (single-flight, last-good on failure).

The client renders nullschool-style particles in a canvas overlay: bilinear
field sampling with longitude wrap, per-frame advection, Cesium camera
projection, and globe-occlusion culling via EllipsoidalOccluder.

Validated end-to-end against the real 2026-09-14 06z cycle on Node 25
(180x91 grid at 2°, 131,040-byte payload, plausible mean |u|/|v|). The WASM
decoder requires Node >=24, which the repo already requires.

Registered as `wind` (token k) with attribution and docs. Verified: npm test
(3412 pass, 0 fail), npm run check:boundaries.

CHANGELOG.md

@@ -103,6 +103,12 @@ of current runtime behavior, see [`docs/CURRENT-STATE.md`](docs/CURRENT-STATE.md
 
 ### Added
 
+- Add a keyless **Wind** layer from NOAA GFS 10 m wind. The `/api/wind` proxy
+  byte-range fetches only the UGRD/VGRD GRIB2 messages from the public AWS bucket,
+  decodes them with ecCodes (WASM), and serves a compact Float32 U/V grid; the
+  client renders nullschool-style animated particles in a canvas overlay that
+  follows the Cesium camera and skips globe-occluded points. Forecast, not
+  observations. Requires Node ≥24 for the WASM decoder.
 - Add Ontario 511 as a keyless CCTV source pack, including Kitchener-area
   highway cameras, with server-registered still URLs and attribution.
 - CCTV Mesh adds Finland: Fintraffic road weather cameras, keyless, nationwide, 300 by default. Each camera view of a station is placed separately; ambient stills refresh on the source's 10-minute cadence (the active camera keeps the usual 10-second refresh).