feat(world): generic dive site scene fed by a baked site definition

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

game/world/sites/dive_site.tscn

@@ -0,0 +1,47 @@
+[gd_scene load_steps=4 format=3]
+
+[ext_resource type="Script" path="res://game/world/sites/dive_site.gd" id="1_site"]
+[ext_resource type="Script" path="res://game/world/sites/bathymetric_terrain_actor.gd" id="2_terrain"]
+
+[sub_resource type="Environment" id="EnvironmentUnderwater"]
+background_mode = 1
+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
+fog_density = 0.014
+fog_height = -4.0
+fog_height_density = 0.025
+volumetric_fog_enabled = true
+volumetric_fog_density = 0.025
+volumetric_fog_length = 72.0
+
+[node name="DiveSite" type="Node3D"]
+script = ExtResource("1_site")
+
+[node name="WorldEnvironment" type="WorldEnvironment" parent="."]
+environment = SubResource("EnvironmentUnderwater")
+
+[node name="AmbientDirection" type="DirectionalLight3D" parent="."]
+rotation_degrees = Vector3(-52, -24, 0)
+light_color = Color(0.39, 0.65, 0.7, 1)
+light_energy = 0.38
+shadow_enabled = true
+
+[node name="Terrain" type="StaticBody3D" parent="."]
+unique_name_in_owner = true
+script = ExtResource("2_terrain")
+
+[node name="Placements" type="Node3D" parent="."]
+unique_name_in_owner = true