M0: Scaffold Theriapolis.Godot project (hello-world)

First milestone of the Godot port. Establishes the new project structure
and verifies the toolchain is wired up end-to-end.

- Godot.NET.Sdk/4.6.2 targeting net8.0; references Theriapolis.Core
- project.godot configured for borderless fullscreen at native resolution
  (per port plan §10 resolved decisions); F11 toggles to windowed
- Main.tscn + Main.cs hello-world; nearest-neighbor texture filtering
- icon.svg placeholder (T in gild on dark)
- Added to Theriapolis.sln

Verification:
- dotnet build Theriapolis.Godot.csproj: 0 errors, 0 warnings
- dotnet build Theriapolis.sln: 0 errors (6 pre-existing warnings unrelated)
- dotnet test: 708/708 pass in 26s (unchanged from master)
- Godot 4.6.2 opens project; fullscreen + F11 toggle confirmed visually

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Theriapolis.Godot/Main.cs

@@ -0,0 +1,23 @@
+using Godot;
+
+namespace Theriapolis.GodotHost;
+
+public partial class Main : Node
+{
+    public override void _Ready()
+    {
+        GD.Print("Theriapolis.Godot host ready (M0 hello-world).");
+    }
+
+    public override void _UnhandledInput(InputEvent @event)
+    {
+        if (@event.IsActionPressed("ui_toggle_fullscreen"))
+        {
+            var mode = DisplayServer.WindowGetMode();
+            DisplayServer.WindowSetMode(
+                mode == DisplayServer.WindowMode.Fullscreen
+                    ? DisplayServer.WindowMode.Windowed
+                    : DisplayServer.WindowMode.Fullscreen);
+        }
+    }
+}

Theriapolis.Godot/Main.tscn

@@ -0,0 +1,20 @@
+[gd_scene load_steps=2 format=3 uid="uid://btheriapolis0m0"]
+
+[ext_resource type="Script" path="res://Main.cs" id="1_main"]
+
+[node name="Main" type="Node"]
+script = ExtResource("1_main")
+
+[node name="Label" type="Label" parent="."]
+anchors_preset = 8
+anchor_left = 0.5
+anchor_top = 0.5
+anchor_right = 0.5
+anchor_bottom = 0.5
+offset_left = -200.0
+offset_top = -16.0
+offset_right = 200.0
+offset_bottom = 16.0
+horizontal_alignment = 1
+vertical_alignment = 1
+text = "Theriapolis · Godot port · M0 · F11 toggles fullscreen"

Theriapolis.Godot/Theriapolis.Godot.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Godot.NET.Sdk/4.6.2">
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <LangVersion>12</LangVersion>
+    <Nullable>enable</Nullable>
+    <EnableDynamicLoading>true</EnableDynamicLoading>
+    <RootNamespace>Theriapolis.GodotHost</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Theriapolis.Core\Theriapolis.Core.csproj" />
+  </ItemGroup>
+</Project>

Theriapolis.Godot/icon.svg

@@ -0,0 +1,5 @@
+<svg width="128" height="128" viewBox="0 0 128 128" xmlns="http://www.w3.org/2000/svg">
+  <rect width="128" height="128" fill="#1c1410"/>
+  <rect x="6" y="6" width="116" height="116" fill="none" stroke="#d8a84a" stroke-width="2"/>
+  <text x="64" y="78" font-family="serif" font-size="64" font-style="italic" fill="#d8a84a" text-anchor="middle">T</text>
+</svg>

Theriapolis.Godot/project.godot

@@ -0,0 +1,39 @@
+; Engine configuration file.
+; Generated for Theriapolis Godot port (M0).
+;
+; Format documentation: https://docs.godotengine.org/en/stable/classes/class_projectsettings.html
+
+config_version=5
+
+[application]
+
+config/name="Theriapolis"
+config/description="Theriapolis — TTRPG worldgen + simulation game (Godot port)."
+run/main_scene="res://Main.tscn"
+config/features=PackedStringArray("4.6", "C#", "Forward Plus")
+config/icon="res://icon.svg"
+
+[display]
+
+; Borderless fullscreen at the primary monitor's native resolution
+; (per port plan §10 resolved decisions). F11 toggles to windowed.
+window/size/mode=3
+window/stretch/mode="canvas_items"
+window/stretch/aspect="expand"
+
+[dotnet]
+
+project/assembly_name="Theriapolis.Godot"
+
+[input]
+
+ui_toggle_fullscreen={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":4194342,"physical_keycode":0,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
+]
+}
+
+[rendering]
+
+renderer/rendering_method="forward_plus"
+textures/canvas_textures/default_texture_filter=0