build: baked lighting pass on kit_demo test map

- Restructured kit_demo.tscn from linear demo to enclosed 5.12x5.12 room
  with walls, floor tiles, pillar, beam, doorway, window
- Added WorldEnvironment with ProceduralSky for ambient lighting
- Added DirectionalLight3D (sun key light, 45° angle, shadows enabled)
- Added OmniLight3D (warm interior fill light)
- Added ReflectionProbe for interior specular reflections
  (box projection, room-sized extents)
- Added LightmapGI with balanced quality settings
  (bounces=3, texel_scale=1.0, max_texture_size=2048, denoiser=true)
- Added tool script (kit_demo.gd) that prints bake status in editor
- Added bake_lighting.gd CLI bake script (requires GPU-enabled instance)
- Updated project.godot with reflection atlas and shadow map quality settings

Headless baking note: Godot's standard editor build requires a GPU/display
for LightmapGI.bake(). Open the scene in the Godot editor and click 'Bake
Lightmap' on the LightmapGI node to generate the baked lightmap data.

client/scripts/bake_lighting.gd

@@ -0,0 +1,70 @@
+extends Node
+
+func _ready():
+	print("=== LightmapGI Baked Lighting Baker ===")
+	print("Opening scene: res://assets/scenes/modular/kit_demo.tscn")
+	
+	# Load the scene
+	var scene = ResourceLoader.load("res://assets/scenes/modular/kit_demo.tscn")
+	if not scene:
+		print("ERROR: Failed to load scene!")
+		get_tree().quit(1)
+		return
+	
+	var instance = scene.instantiate()
+	get_tree().root.add_child(instance)
+	
+	# Find the LightmapGI node
+	var lightmap = instance.find_child("LightmapGI", true, false)
+	if not lightmap:
+		print("ERROR: No LightmapGI node found in scene!")
+		get_tree().quit(1)
+		return
+	
+	if not lightmap is LightmapGI:
+		print("ERROR: Found node 'LightmapGI' is not a LightmapGI type!")
+		get_tree().quit(1)
+		return
+	
+	print("LightmapGI found. Configuration:")
+	print("  Bounces: ", lightmap.bounces)
+	print("  Texel Scale: ", lightmap.texel_scale)
+	print("  Texel Subdiv: ", lightmap.texel_subdiv)
+	print("  Max Texture Size: ", lightmap.max_texture_size)
+	print("  Interior: ", lightmap.interior)
+	
+	# Start baking
+	print("")
+	print("=== Starting LightmapGI bake ===")
+	print("(This may take a while...)")
+	
+	# Wait one frame for scene to fully initialize
+	await get_tree().process_frame
+	
+	var result = lightmap.bake(instance, null)
+	
+	if result != OK:
+		print("ERROR: Lightmap bake failed with error code: ", result)
+		get_tree().quit(1)
+		return
+	
+	print("")
+	print("=== Lightmap bake successful! ===")
+	
+	# Save the scene with baked data
+	print("Saving scene with baked lightmap data...")
+	var packed = PackedScene.new()
+	packed.pack(instance)
+	var save_result = ResourceSaver.save(packed, "res://assets/scenes/modular/kit_demo.tscn")
+	
+	if save_result != OK:
+		print("ERROR: Failed to save scene! Error code: ", save_result)
+		get_tree().quit(1)
+		return
+	
+	print("Scene saved successfully!")
+	print("Baked lighting data is now embedded in kit_demo.tscn")
+	print("(The LightmapGI node's light_data property contains the baked data)")
+	print("")
+	print("=== Done ===")
+	get_tree().quit(0)

client/scripts/test_headless.gd

@@ -0,0 +1,6 @@
+extends Node
+
+func _ready():
+	print("Hello from Godot headless script!")
+	print("Testing: ", Engine.get_version_info())
+	get_tree().quit(0)