feat(wind-farm): add the wind farm explainer

[veelenga]

Overview

• add the wind-farm explainer: one made-up day of wind on an onshore farm of 27 Vestas V150-4.2 MW turbines sized like Målarberget, told in six chapters (the farm from above, the tower and blades, inside the nacelle, catching the wind, wakes and spacing, the road to the grid)
• two dioramas in one assembly, switched by the chapter: a detailed single turbine with a nacelle cutaway (hub and pitch cylinders, main bearing, main shaft, three-stage gearbox, disc brake, generator, converter, yaw drives, cooler) and the whole farm with instanced turbines, wake plumes, flowing collector cables, a substation and the grid line, on painted rolling farmland with woods and a sky dome
• model from a sourced facts sheet: a 24-hour wind profile with three site scales and a shared storm, the maker's power and thrust curves, cut-in, full power, ramp-down, cut-out, feathering, parking and restart with hysteresis, a Jensen wake model over the farm layout for three spacings, wind shear with height, day energy, capacity factor and homes supplied
• controls: a site wind choice, toggles for airflow, wakes, cables and labels, chapter chips for the wind, the nacelle cover and the row spacing, two wind sliders, a power-curve canvas with the Betz line, and gauge readouts for the wind, one turbine and the whole farm
• copy in all eight languages, reviewed, then rewritten twice from the English meaning by a native writer each, with zero dashes and descriptions within the limits
• cover and link preview image
• build: replace three's TessellateModifier with a small subdivide helper so the shared chunk stays within the budget

Notes

Lint, the full test suite (3,858 tests) and the build with the site check pass. The wind-farm page loads about 284 kB of gzipped JavaScript against the 300 kB budget.

Browser QA on desktop 1440 × 900 and a 390 × 844 phone in English, Ukrainian and Japanese: no page or console errors, no untranslated keys, no horizontal overflow, every dock choice, toggle, chip row and slider checked on the real scene, the scene swap between farm and turbine chapters, and free orbit from above, behind and the far side in every chapter.

Known rough edges: the farm turbines are small in the cover thumbnail, the core label layout can keep a crowded label hidden until the camera moves, and the "Yaw drives" label sometimes drops out as crowded on a phone.