Overview

Replace hardcoded C:\Windows\Fonts\ paths used for ImGui UI font loading with a cross-platform font resolution strategy.

Files Affected

• FModel/Framework/ImGuiController.cs

Findings

• ImGui fonts loaded from: @"C:\Windows\Fonts\segoeui.ttf", @"C:\Windows\Fonts\segoeuib.ttf", @"C:\Windows\Fonts\seguisb.ttf"
• These paths do not exist on Linux; ImGui.GetIO().Fonts.AddFontFromFileTTF() returns null, causing the entire ImGui render pass to fail with a null-reference exception
• Resolution options (in priority order):
  1. Bundle a permissively-licensed substitute font (e.g. Inter, Noto Sans) as an embedded resource in FModel/Resources/ → call AddFontFromMemoryTTF() from stream
  2. Probe fc-match "Segoe UI" on Linux and fall back to the system sans-serif path
• On Windows: retain existing Segoe UI path; on Linux: use bundled/probed font

Acceptance Criteria

• ImGui renders on Linux with a legible UI font
• No hardcoded C:\Windows\Fonts\ path remains
• No null ImFont crash on Linux

Effort

M (1–4 hours)

Agent

platform-abstraction-specialist

Depends On

• P1-001 ([P1-001] Migrate project file from net8.0-windows to net8.0 #7)