feat(cockpit): replace procedural cockpit with twelve scripted models

Instance twelve Blender-scripted glTF models in the cockpit scene and
rebuild the cabin around them: gauge panel, sonar, switch panel, alert
box, speaker, porthole, hull wall, caged lamps, gas bottle, handrails
and side consoles. Presentation only; no domain, application or world
rule changes beyond enabling glow in the test environment.

- Needles, alert lamps and sonar screen are driven by the existing
  snapshots; the alert box now carries SYS/ATTN/ALRM.
- Depth dial reads percent of certified depth.
- Sonar display restyled as a turquoise holographic relief with a
  shader grid and height scale; SubViewport matches the glass (960x604).
- Cabin lighting retuned: warm pooled lamp light, cool porthole rim,
  lamp shadows, dial backlight.
- Procedural stand-ins removed (bulkhead, tanks, consoles, levers,
  indicator columns, placeholder pipe run, dial face PNGs).
- Tests adapted where nodes disappeared; one assertion removed
  (pipe_segment_count) until the pipe kit is placed.
- Model .glb files are committed without LFS; textures Godot extracts
  next to them at import are ignored.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

game/world/sites/vehicle_test_environment.tscn

@@ -8,6 +8,14 @@ background_color = Color(0.005, 0.045, 0.065, 1)
 ambient_light_source = 3
 ambient_light_color = Color(0.12, 0.32, 0.37, 1)
 ambient_light_energy = 0.42
+glow_enabled = true
+glow_levels/1 = 1.0
+glow_levels/2 = 1.0
+glow_levels/3 = 0.6
+glow_levels/4 = 0.2
+glow_intensity = 1.0
+glow_blend_mode = 0
+glow_hdr_threshold = 1.0
 fog_enabled = true
 fog_light_color = Color(0.07, 0.25, 0.3, 1)
 fog_light_energy = 0.48