Armor texture starter files

Files:
- infernal_sovereign.png
- infernal_sovereign_emissive.png
- infernal_sovereign_glowmask.png
- palettes/infernal_sovereign.gpl

Workflow:
1. Open infernal_sovereign.png and paint full detail.
2. Keep infernal_sovereign_emissive.png black except glow regions.
3. Keep infernal_sovereign_glowmask.png synced to the emissive regions.
4. Use nearest-neighbor scaling only.
5. Keep all armor textures at 128x128.
6. Keep emissive coverage under roughly 8% of pixels.

Suggested glow regions:
- Helmet visor slit
- Chest core
- Thin lava seam accents
