Bring in Godot project + address review feedback (this branch had none of it)

This branch never actually had the Godot scaffold — a workspace-reuse bug
(see agp source repo) let leftover backend/**/__pycache__/*.pyc files from
an unrelated task get swept into this branch's only prior commit, which
was checkpointed under this task's title despite containing zero Godot
files. Removing that garbage and bringing over the real project from
agent/997c429bc6b4 (the original PR's branch) with the review feedback
addressed:

- Play button no longer references the nonexistent scenes/game.tscn.
- Wired PlayButton/QuitButton [connection] entries in main_menu.tscn.
- Removed the invalid uid="uid://main_menu".
- Added .gitignore for .godot/.
- Removed the non-standard [export]/[export_options] sections from
  project.godot (Godot 4 uses export_presets.cfg, not this).

.gitignore

@@ -0,0 +1,2 @@
+# Godot 4 editor cache/import directory
+.godot/

project.godot

@@ -0,0 +1,24 @@
+; Engine configuration file.
+; It's best edited using the editor UI and not directly,
+; but it can also be edited by hand.
+
+config_version=5
+
+[application]
+
+config/name="AGP-Game"
+run/main_scene="res://scenes/main_menu.tscn"
+config/features=PackedStringArray("4.6.2")
+
+[autoload]
+
+[display]
+
+window/size/viewport_width=1920
+window/size/viewport_height=1080
+window/stretch/mode="canvas_items"
+
+[rendering]
+
+renderer/rendering_method="gl_compatibility"
+renderer/rendering_method.mobile="gl_compatibility"

scenes/main_menu.tscn

@@ -0,0 +1,43 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://scripts/main_menu.gd" id="1_main"]
+
+[node name="MainMenu" type="Control"]
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_main")
+
+[node name="CenterContainer" type="CenterContainer" parent="."]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+
+[node name="VBoxContainer" type="VBoxContainer" parent="CenterContainer"]
+layout_mode = 1
+theme_override_constants/separation = 16
+size_flags_horizontal = 4
+
+[node name="TitleLabel" type="Label" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+text = "AGP Game"
+horizontal_alignment = 1
+theme_override_font_sizes/font_size = 72
+
+[node name="PlayButton" type="Button" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+text = "Play"
+size_flags_horizontal = 4
+
+[node name="QuitButton" type="Button" parent="CenterContainer/VBoxContainer"]
+layout_mode = 1
+text = "Quit"
+size_flags_horizontal = 4
+
+[connection signal="pressed" from="CenterContainer/VBoxContainer/PlayButton" to="." method="_on_play_button_pressed"]
+[connection signal="pressed" from="CenterContainer/VBoxContainer/QuitButton" to="." method="_on_quit_button_pressed"]

scripts/main_menu.gd

@@ -0,0 +1,14 @@
+extends Control
+
+
+func _ready():
+	pass
+
+
+func _on_play_button_pressed():
+	# No gameplay scene exists yet — wire this to the real scene once one lands.
+	print("Play pressed — no gameplay scene yet")
+
+
+func _on_quit_button_pressed():
+	get_tree().quit()