Add ECMWF IFS 10 m wind alongside NOAA GFS, selectable at runtime.
The /api/wind proxy becomes a model dispatcher: `?model=gfs|ifs` (default gfs,
unknown → 400), cached per model+cycle+grid. IFS reads the keyless ECMWF Open
Data JSON Lines `.index` (note: `<stem>.index`, not `<grib2>.index`), byte-range
fetches only the `10u`/`10v` messages, decodes them with the same ecCodes WASM
path, and resamples with the existing grid code (ECMWF grids start at lo1=180;
the resampler already wraps columns).
The client layer gains a `model` parameter (setParams/getParams) with a
generation guard so a model switch aborts and refetches exactly once. Registered
as an enabled+options layer with a `model` enum.
Validated end-to-end against the real 2026-09-14 06z IFS cycle on Node 25
(180x91 grid at 2°, 131,040-byte payload, plausible mean |u|/|v|), and GFS
still passes the same check.
Attribution: contains modified Copernicus/ECMWF IFS forecast data, licensed
under CC BY 4.0. Verified: npm test (3412 pass, 0 fail), check:boundaries.
Bilawal Sidhu