Docs: the E-ink section describes the landscape and portrait builds, what
the tall screens add, and the settings, with three screenshots; the e-ink
build flags; the release file names. Sim: each orientation gets its own
factory, so a page can load both, and simEinkScale 0 leaves the canvas'
CSS size to the page. CI builds both into solo-sim-wasm.zip (wasm/eink/).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
