Generify the snapping/modifier HUD off the FSM scope and node declarations
instead of wall-creation-shaped, leaking pills.
- Per-context snapping (`snappingModeByContext`, persisted): wall / item /
polygon mode-sets with exclusive modes (grid | lines | angles | off), each
doing exactly what its chip says. Context is node-declared via the new
`NodeDefinition.snapProfile` ('item' | 'structural'); the resolver maps
(profile × action) → context with no per-kind switch.
- Scope-driven HUD: helper-manager reads the interaction scope; reshaping
(endpoint/curve/boundary) and item move get their own chip, no select-hint
leak. Rotate R/T rounds to 45°; Alt = force-place only (hidden for
structural kinds); Shift = cycle everywhere.
- Slab/ceiling drafting: Shift=cycle, mode-aware grid/angle, Enter finishes
(minDraftVertices); polygon boundary vertex/edge drag begins a reshaping
scope. Fix grid/angle being ignored on boundary edit + slab creation:
make resolveSurfacePlanPointSnap exclusive (alignment gated on magnetic) so
grid/angles keep the snapped fallback instead of the raw cursor.
- Painter application scope: node-derived (single/object/matching/room) from
the hovered node, cyclable via Shift, single-source HUD chip.
- Remove the redundant GridSnapControl from view-toggles (grid step lives in
the contextual HUD now).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>