Initial commit: SpaceshipTest, a top-down space RTS in Godot 4.7.1

A fleet of neon-outlined ships explores a procedurally generated, seeded
infinite world: tap/joystick steering, pinch zoom, formation pivoting,
planet landings, an ore economy with extractors and haulers, and player
built structures (mothership, ship crafter, command centre).

All art is hand-drawn with draw_* calls rather than textures, and the
backgrounds are camera-relative shaders so they stay precise at large
world coordinates.

Includes a 35-test headless suite (tests/run_tests.sh) plus screenshot
tooling that renders real frames through Xvfb and Mesa softpipe, since
--headless has no GPU.

Excluded from version control: .godot/ (import cache, and it holds
export credentials), builds/, android/build/ and packaged APKs - all
regenerable, and ~325 MB combined.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

EnemySpawner.gd

@@ -0,0 +1,42 @@
+extends Node2D
+
+@export var min_spawn_interval: float = 3.0
+@export var max_spawn_interval: float = 6.0
+@export var spawn_margin: float = 150.0
+
+@onready var fleet: Node2D = get_node("../Fleet")
+
+var enemy_scene: PackedScene = preload("res://Enemy.tscn")
+var timer: float = 0.0
+var next_spawn_time: float = 0.0
+
+
+func _ready() -> void:
+	randomize()
+	_reset_timer()
+
+
+func _process(delta: float) -> void:
+	timer += delta
+	if timer >= next_spawn_time:
+		timer = 0.0
+		_reset_timer()
+		_spawn_enemy()
+
+
+func _reset_timer() -> void:
+	next_spawn_time = randf_range(min_spawn_interval, max_spawn_interval)
+
+
+func _spawn_enemy() -> void:
+	if fleet.ships.is_empty():
+		return
+
+	var visible_rect: Rect2 = ViewUtils.get_visible_world_rect(self)
+	var radius: float = visible_rect.size.length() / 2.0 + spawn_margin
+	var angle: float = randf() * TAU
+	var spawn_pos: Vector2 = fleet.get_centroid() + Vector2(cos(angle), sin(angle)) * radius
+
+	var enemy: Node2D = enemy_scene.instantiate()
+	enemy.position = spawn_pos
+	get_parent().add_child(enemy)