feat: nodes material system and bug fix

[sudhir9297]

What does this PR do?

This PR upgrades the material system and interaction model across walls, stairs, roofs, and slabs by introducing multi-surface material support, click-targeted editing, and improved rendering stability.

It enables:

• Independent material control for different surfaces (walls, stairs, roofs)
• Direct click-based material editing in 3D instead of panel-only workflows
• Backward compatibility with existing single-material objects
• Improved UV handling and rendering consistency across all geometry types
• Better selection, highlighting, and editing UX aligned with multi-surface materials

All updates are integrated into the existing architecture without introducing new state systems.

---

Walls

• Added first-class two-sided wall material support for interior and exterior faces.
• Kept wall top, bottom, end caps, and opening reveals on the base structural material.
• Added backward-compatible migration from legacy single-material walls.
• Updated wall merge logic so only walls with matching side-specific materials can merge.
• Switched wall rendering to grouped/material-array rendering.
• Updated wall cutaway and highlight behavior to support material arrays.
• Restored wall panel to a single Material control instead of separate side pickers.
• Added click-targeted wall-face editing in 3D (interior vs exterior).
• Standardized wall panel actions (Move, Curve) into the shared Actions section.

---

Stairs

• Added multi-surface stair material support for straight stairs:
  • Railing
  • Tread
  • Side / underside
• Added backward-compatible migration from legacy single-material stairs.
• Grouped stair geometry into tread vs side/underside regions.
• Updated stair rendering so railing and stair body materials resolve independently.
• Replaced separate stair material sections with click-targeted editing flow.
• Added click-targeted material selection for:
  • Railing
  • Tread
  • Side / underside
• Extended click-targeted editing to curved and spiral stairs.
• Made curved/spiral center pillar selectable and mapped to side/underside material.
• Fixed BVH/material crashes caused by mismatched placeholder geometry.
• Replaced problematic placeholders with grouped empty geometries where required.
• Fixed UV generation for straight stairs.
• Fixed UV generation for curved and spiral stairs.
• Added uv2 support for materials requiring secondary UVs.

---

Roofs

• Added three logical roof material targets:
  • Top
  • Edge
  • Wall
• Mapped inner wall-length faces to the wall material target.
• Added backward-compatible migration from legacy single-material roofs.
• Updated roof rendering to use grouped material arrays.
• Added click-targeted roof material editing for:
  • Top faces
  • Edge faces
  • Inner wall-length faces
• Kept roof panel as a single Material section (no duplication).
• Fixed roof selection so merged roofs remain visually consistent.
• Limited segment visualization to actual selected segments.
• Fixed "Add Segment" UI to match shared action layout.

---

Roof Materials

• Added new materials: wood1, wood2, wood3 to roof material picker.
• Fixed roof UV generation.
• Ensured UVs persist through geometry/CSG operations.
• Added uv2 support for final roof geometry and segments.

---

Site / Ground Visuals

• Investigated ghost/inverted footprint visible on ground grid.
• Identified it as site ground masking behavior (not real geometry).
• Removed the visual artifact so slabs no longer show ghost shapes.

---

Fence UVs

• Fixed fence UV stretching issue.
• Replaced single normalized projection with per-part UV mapping.
• Applied unit-based mapping so rails/posts scale correctly.

---

Selection / Material Infrastructure

• Extended shared selection system to support click-targeted material workflows.
• Updated highlight and selection behavior to align with multi-surface materials across walls, stairs, and roofs.

---

Slab Material Fix & Stability

• Investigated slab material loss after refresh.
• Identified issue: material cloning before texture load caused fallback color rendering.
• Fixed by applying preset materials directly to slab-owned material instances.
• Ensured textures load correctly and persist visually after refresh.

---

Slider & Interaction Improvements

• Updated wall Curve slider default step from 0.01m to 0.1m.
• Standardized slider modifier behavior:
  • Cmd/Ctrl → 0.01
  • Shift → 1
  • Default → base step
• Applied consistent modifier behavior across:
  • Drag
  • Mouse wheel
  • Arrow keys
  • Inline numeric input

[wass08]

Thank you! Need some changes before being merge-ready.
Also wasn't sure if having the material assignation in the renderer is better than in the system to prevent re-renders but we can keep it for now

[wass08]

Pass the object in the event, and let the events needing this extra computation do it only when needed

[sudhir9297]

update.

[wass08]

could be replaced by selectedMaterialTarget with a generic type (and as we know the selected object we can deduct what type of node we're on) use AnyNodeId instead of roofNode['id'], wallNode['id']

[sudhir9297]

made the necessary changes.

[wass08]

Let's go!