Fix column numbering convention and 3D viewer improvements

[mbreiser]

Context

Follow-up work from the 2026-01-24 web tools UI redesign session.

Issues to Fix

1. Column #0 Convention (Both MATLAB & Web)

• Column 0 should always be at the 'bottom' of the display (south position)
• Fly view should always look north
• angle_offset_deg needs to be redefined relative to this convention
• Affects: arena_editor.html, arena_3d_viewer.html, design_arena.m
• NOTE: Will likely need to update most/all standard arena configs in configs/arenas/ once column reference is changed

2. 3D Viewer Label Occlusion

• Currently labels float freely and can be confusing
• Labels should render WITH occlusions (hidden by panels when behind them)
• This helps users understand spatial relationships
• May need to switch from CSS2DRenderer to sprite-based labels or use depth testing

Files to Update

• arena_editor.html - Column numbering
• arena_3d_viewer.html - Column numbering + label occlusion
• maDisplayTools/utils/design_arena.m - Column numbering convention
• maDisplayTools/configs/arenas/*.yaml - Review/update angle_offset_deg values for all configs

Related

• Session notes: docs/G4G6_ROADMAP.md (2026-01-24 PM session)
• Plan file: .claude/plans/spicy-wandering-wall.md

[mbreiser]

In matlab visualize arenas, should plot column number just behind each panel (outside the ring) to be able to standardize configs before moving over to web tools

Also add caveat about older generations not being fully tested