Geometric-dislike ('Push away', Mode 1) is now the default feedback mode
instead of explore-and-place, which works poorly. Add a Clear button to
the Learning drawer that forgets all recorded examples and wipes the
on-map visuals (feedback markers + placed-anchor pins) via the existing
ctx.onClear, now also resetting pins.
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').
