Add developers/.gdignore; let Godot 4 canonicalise saved scenes

The developers/aurelien sandbox scenes still reference legacy non-LOD
mesh paths (sm_book.mesh, sm_candlestick.mesh, ...) that don't exist
anymore — the production scenes were migrated to *_lod0/1/2.mesh.
Godot's full-project file scanner reads every .tscn at editor open
and emits 'Cannot open file' errors for each broken ext_resource,
even for scenes that the game never loads.

Mark developers/ as out-of-scope for Godot's filesystem walker with
a .gdignore at its root. The .import / .uid sidecars Godot had
generated for files inside (CheckLightmap.exr.import,
CheckLightmap.gd.uid) are auto-removed by the editor since they are
now orphaned metadata — only the source files (.tscn, .gd, .exr,
.lmbake) remain. Re-enabling the sandbox later just means deleting
the .gdignore; Godot will regenerate the sidecars.

The other diffs in this commit are Godot 4 canonicalising whatever
.tscn / .tres files were touched in the editor session that ran the
LightmapGI bake attempt: ext_resource uid= attributes added, format
bumped 2 -> 3, property order normalised. No behavioural change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scenes/levels/parts/ListObjects.tscn

@@ -1,10 +1,10 @@
-[gd_scene format=3]
+[gd_scene format=3 uid="uid://bgqkui3o0tkfq"]
 
 [ext_resource type="Theme" path="res://assets/ui/themes/leather.theme" id="2"]
-[ext_resource type="FontVariation" path="res://assets/fonts/kirsty/kirsty_base.tres" id="3"]
-[ext_resource type="Texture2D" path="res://assets/ui/icones/skull.png" id="4"]
-[ext_resource type="Texture2D" path="res://assets/ui/themes/UI-Button-ItemsList-last-hover.png" id="6"]
-[ext_resource type="Texture2D" path="res://assets/ui/themes/UI-Button-ItemsList-last.png" id="8"]
+[ext_resource type="FontVariation" uid="uid://inv1rofq17xy" path="res://assets/fonts/kirsty/kirsty_base.tres" id="3"]
+[ext_resource type="Texture2D" uid="uid://dn8uon4qa6naj" path="res://assets/ui/icones/skull.png" id="4"]
+[ext_resource type="Texture2D" uid="uid://b6qxaqvf46lvy" path="res://assets/ui/themes/UI-Button-ItemsList-last-hover.png" id="6"]
+[ext_resource type="Texture2D" uid="uid://dxd25u6105236" path="res://assets/ui/themes/UI-Button-ItemsList-last.png" id="8"]
 
 [sub_resource type="Animation" id="1"]
 resource_name = "ObjectFind"
@@ -33,7 +33,14 @@ tracks/0/keys = {
 "times": PackedFloat32Array(0, 1)
 }
 
-[node name="Control" type="MarginContainer"]
+[sub_resource type="AnimationLibrary" id="AnimationLibrary_vpan8"]
+_data = {
+&"ObjectFind": SubResource("1"),
+&"ObjectFindAll": SubResource("2")
+}
+
+[node name="Control" type="MarginContainer" unique_id=316364814]
+anchors_preset = 6
 anchor_left = 1.0
 anchor_top = 0.5
 anchor_right = 1.0
@@ -44,30 +51,25 @@ offset_bottom = 450.0
 grow_horizontal = 0
 grow_vertical = 2
 size_flags_vertical = 3
-__meta__ = {
-"_edit_use_anchors_": false
-}
 
-[node name="ListContainer" type="VBoxContainer" parent="."]
-offset_right = 196.0
-offset_bottom = 900.0
+[node name="ListContainer" type="VBoxContainer" parent="." unique_id=10094609]
 custom_minimum_size = Vector2(196, 900)
+layout_mode = 2
 size_flags_horizontal = 3
 size_flags_vertical = 3
 theme_override_constants/separation = -14
 alignment = 1
 
-[node name="TextureButtonLast" type="TextureButton" parent="ListContainer"]
+[node name="TextureButtonLast" type="TextureButton" parent="ListContainer" unique_id=129456161]
 visible = false
-offset_top = 409.0
-offset_right = 196.0
-offset_bottom = 490.0
+layout_mode = 2
 focus_mode = 0
 texture_normal = ExtResource("8")
 texture_hover = ExtResource("6")
 texture_focused = ExtResource("6")
 
-[node name="Label" type="Label" parent="ListContainer/TextureButtonLast"]
+[node name="Label" type="Label" parent="ListContainer/TextureButtonLast" unique_id=172840960]
+layout_mode = 0
 anchor_right = 1.0
 anchor_bottom = 1.0
 theme = ExtResource("2")
@@ -75,23 +77,15 @@ theme_override_fonts/font = ExtResource("3")
 text = "Last"
 horizontal_alignment = 1
 vertical_alignment = 1
-__meta__ = {
-"_edit_use_anchors_": false
-}
 
-[node name="HBoxContainer" type="HBoxContainer" parent="ListContainer"]
+[node name="HBoxContainer" type="HBoxContainer" parent="ListContainer" unique_id=1143563347]
 visible = false
-offset_top = 419.0
-offset_right = 196.0
-offset_bottom = 547.0
+layout_mode = 2
 alignment = 1
 
-[node name="TextureButtonIndice" type="TextureButton" parent="ListContainer/HBoxContainer"]
-offset_left = 34.0
-offset_right = 162.0
-offset_bottom = 128.0
+[node name="TextureButtonIndice" type="TextureButton" parent="ListContainer/HBoxContainer" unique_id=273706555]
+layout_mode = 2
 texture_normal = ExtResource("4")
 
-[node name="AnimationPlayer" type="AnimationPlayer" parent="."]
-anims/ObjectFind = SubResource("1")
-anims/ObjectFindAll = SubResource("2")
+[node name="AnimationPlayer" type="AnimationPlayer" parent="." unique_id=360897851]
+libraries/ = SubResource("AnimationLibrary_vpan8")