Single-file map of the Manifold front-end so an agent can make a tweak/fix
without re-grepping the tree or reading the 40KB design specs: run/build/
deploy/test commands, the three-layer architecture (UI / engine spine / WASM),
the convertible Stage system, the Dock + drawers, engine/inputs/feedback/
backends layout, and the non-obvious gotchas (imperative output reads,
baseURI asset URLs, hardwired WASM arch, curves↔C++ lockstep, no 'C15').
