Feat/improvement and fixes

[sudhir9297]

What does this PR do?

This PR introduces a reference overlay workflow for the 2D floorplan editor, along with improvements to door rendering, dark-mode visuals, item symbols, and overall 2D geometry consistency, also drag-and-drop floor reordering in the floating level selector and significantly upgrades door and window systems across 2D, 3D, and first-person workflows.

It enables:

• Local-first image overlays with scale calibration for tracing floorplans
• Lower-floor reference overlays for multi-level alignment
• Cleaner, more accurate 2D rendering for doors, slabs, stairs, and items
• Improved dark-mode visibility and visual consistency
• Better alignment between 2D visuals and actual 3D geometry
• Manual floor reordering via drag-and-drop
• More realistic door behavior (hinge-based rotation, interaction, collision)
• Flexible door/window opening types (rect, rounded, arch)
• Improved 2D symbols and visual clarity
• Better first-person interaction and walk-through logic

---

Floor Reordering (Floating Level Selector)

• Added drag-and-drop support for floor reordering.
• Added six-dot drag handle for each floor item.
• Kept normal floor selection separate from drag interaction.
• Reordered floors using existing editor state flow.
• Allows repositioning of duplicated or newly created floors.

---

Door System

• Updated door rotation:
  • Uses hinge-based swing instead of center rotation
• Added support for:
  • Door vs Opening modes
  • Opening types: Rect, Rounded, Arch
• Added rounded opening controls:
  • All corners or individual top-corner radius
• Enabled live radius updates during drag (commit on release)
• Improved 2D door symbol:
  • Lighter styling
  • Swing wedge
  • Hinge and strike markers
  • Selected circular marker
  • Clearer opening representation
• Changed 2D opening fill to white (instead of grey)
• Made door openings walk-through in first-person
• Updated open-door collider to match actual swinging leaf
• Added first-person interaction:
  • Press E to open/close doors
• Fixed collider merge issues by normalizing geometry
• Improved 3D selection with deeper transparent hitbox
• Removed visible door root hitbox material

---

Window System

• Added support for:
  • Window vs Opening modes
  • Opening types: Rect, Rounded, Arch
• Added rounded corner controls:
  • All corners or individual control
• Enabled auto-fitting of rounded radii on size changes
• Removed first-person collider (fully walk-through)
• Rendered window openings as pure cutouts (no frame/glass/sill)
• Added 2D floorplan opening symbol for windows

---

Interaction & Controls

• Fixed width/height sliders:
  • No snapping or resetting on drag release
• Improved consistency across door and window editing workflows

---

Image Overlay & Reference Scale

• Implemented local-first image overlay workflow using guide nodes.
• Added overlay-specific fields:
  • locked
  • showIn3d
  • scaleReference
• Enabled local image upload via IndexedDB-backed asset system.
• Added guide controls:
  • Replace / delete image
  • Show / hide
  • Lock / unlock
  • Opacity
  • Set / edit / clear scale
  • Reset image scale
• Added reference scale calibration flow:
  • Click start and end points
  • Enter real-world length and units
  • Store calibrated scale
• Rendered scale reference in 2D:
  • Dashed line
  • Endpoint markers
  • Label
  • Live preview
• Applied calibration to image scaling (non-destructive to geometry).
• Auto-locks overlay after calibration.
• Added locked overlay behavior so drawing does not interfere with clicks.
• Added guide selection via bottom dropdown.
• Improved tracing visibility by reducing slab/ceiling fill strength.
• Updated selected wall styling (white fill + blue hatch).
• Added optional 3D visibility toggle for overlays.

---

Reference Floor Overlay

• Added lower-floor reference overlay in 2D floorplan.
• Persisted state:
  • Visibility
  • Selected level offset
  • Opacity
• Added Reference Floor control with level selection dropdown.
• Displayed level names with fallback labels.
• Rendered lower level as locked, non-interactive underlay.
• Included:
  • Walls, slabs, ceilings, fences
  • Openings and item footprints
• Limited overlay to floors below active level.

---

Door Rendering (2D)

• Adjusted door leaf length to align with swing radius.
• Replaced curve with true circular SVG arc.
• Unified stroke styling across door elements.
• Reduced wall-aligned background depth for cleaner visuals.
• Switched to theme-aware stroke colors.
• Removed unused geometry variables.

---

Dark Mode & Item Visuals

• Improved dark-mode contrast across:
  • Walls, slabs, ceilings, stairs, roofs, measurements
• Updated renderers to use theme-aware colors.
• Added custom 2D SVGs:
  • Office chair
  • Sofa
• Applied SVG overrides to existing items.
• Removed extra footprint borders for self-outlined SVG items.
• Refined hover/selection highlight thickness.
• Improved sofa SVG details and consistency.

---

Geometry & Rendering Fixes (2D)

• Fixed rotation issues:
  • Vegetation/item footprints
  • Spiral/curved stairs
• Improved spiral stair rendering alignment and boundaries.
• Synced slab 2D rendering with actual 3D geometry.
• Hid grid under slabs while preserving cutouts.
• Updated slab styling:
  • Light fill
  • Neutral border
  • Consistent stroke width
• Added selection styling:
  • Blue highlight
  • Diagonal hatch lines (thinner)
• Increased slab label font size.
• Fixed slab edit handles to align with visible boundaries.
• Exported shared slab polygon logic for reuse.