Direct copy of the fence curve recipe — pure
`curveWallDragAction` (chord-perpendicular projection + clamp +
normalize + single-undo dance) plus a thin wrapper feeding
`useDragAction`. Mounted via `def.affordanceTools.curve`.
Slight precision difference vs legacy: the legacy CurveWallTool snapped
the pointer position to `getWallGridStep()` before projecting onto the
chord normal; the ported action skips that pre-snap and relies on
`normalizeWallCurveOffset` to settle the final value. The user-visible
result is the same magnitude of step, just with the snap applied at
the offset level instead of the position level.
Remaining wall D affordances (endpoint move, whole-wall move,
placement) are larger and queued for future sessions — wall's move
tool alone is 804 LoC with the linked-wall corner-cascade logic.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
