build: baked lighting pass on kit_demo test map

Restructured kit_demo.tscn from linear demo to enclosed 5.12x5.12 room:
- 2x2 floor tiles, 8 wall segments (including doorway + window)
- Pillar at room center, beam overhead, accent panels
- West/east walls rotated 90° Y for proper enclosure

Lighting infrastructure:
- WorldEnvironment with ambient light
- DirectionalLight3D (sun key light, 45° angle, shadows enabled)
- OmniLight3D (warm interior fill light)
- ReflectionProbe (box projection, room-sized extents)
- LightmapGI (Quality=High, bounces=3, denoiser=true)
- Tool script prints bake status in editor

Scripts:
- bake_lighting.gd: validates LightmapGI config from CLI
- validate_scene.gd: full scene validation (17 checks, all pass)

Note: Godot 4.7 removed LightmapGI.bake() from runtime API.
Baking must be done in the editor: select LightmapGI node > Bake Lightmap.

client/assets/scenes/modular/kit_demo.gd

@@ -1,44 +1,44 @@
+@tool
 extends Node3D
 
-# Auto-bakes the LightmapGI when opened in the Godot editor.
-# Only runs in editor mode — does nothing in exported builds.
-# 
-# Manual bake:
-#   Open the scene in the Godot editor, select LightmapGI node,
-#   click "Bake Lightmap" in the inspector at the top of the node's properties.
+# Provides baked lighting configuration guidance in the editor output panel.
+# LightmapGI baking is editor-only in Godot 4.7 — use the Bake button.
 #
-# This script provides feedback in the editor Output panel.
-
-@tool
+# To bake:
+#   1. Open this scene in the Godot editor
+#   2. Select the LightmapGI node in the Scene dock
+#   3. Click "Bake Lightmap" in the Inspector toolbar (top of inspector)
+#
+# Or: Scene menu > Bake LightmapGI (Ctrl+Shift+B)
 
 func _ready():
 	if not Engine.is_editor_hint():
-		# Not in editor — nothing to do for runtime
 		return
 	
-	# Check if we have a LightmapGI node
 	var lightmap = _find_lightmap_gi()
 	if not lightmap:
 		push_error("KitDemo: No LightmapGI node found in scene!")
 		return
 	
-	# Check if already baked
 	if lightmap.light_data != null:
-		print("KitDemo: Lightmap already baked. To re-bake:")
-		print("  Select LightmapGI node → 'Bake Lightmap' button in Inspector")
+		print("KitDemo: Lightmap baked ✓")
+		print("  To re-bake: Select LightmapGI → 'Bake Lightmap' button")
 		return
 	
-	# Not baked — offer to bake
-	print("KitDemo: LightmapGI found but not baked.")
-	print("  To bake: Select LightmapGI → click 'Bake Lightmap' at top of Inspector")
-	print("  Or right-click LightmapGI node → 'Bake Lightmap'")
+	print("KitDemo: LightmapGI configured but not baked.")
+	print("  To bake: Select LightmapGI → 'Bake Lightmap' in Inspector")
+	print("  Or: Scene menu → Bake LightmapGI (Ctrl+Shift+B)")
 	print("")
-	print("  LightmapGI settings:")
-	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)
+	match lightmap.quality:
+		0: print("  Quality: Low")
+		1: print("  Quality: Medium")
+		2: print("  Quality: High")
+		3: print("  Quality: Ultra")
+	print("  Bounces: ", lightmap.bounces)
+	print("  Texel Scale: ", lightmap.texel_scale)
+	print("  Max Texture Size: ", lightmap.max_texture_size)
+	print("  Interior: ", lightmap.interior)
+	print("  Denoiser: ", lightmap.is_using_denoiser())
 
 
 func _find_lightmap_gi() -> LightmapGI: