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>

tests/_crafter_preview.gd

@@ -0,0 +1,41 @@
+extends Node2D
+
+# Preview scene for eyeballing building art - NOT run by run_tests.sh
+# (underscore prefix). Lays out the mothership and command centre alongside
+# several phases of the ship crafter's assembly cycle, with the crafter's
+# _process disabled and anim_time pinned, so a single softpipe render shows
+# the whole animation at once (the renderer is far too slow here to time a
+# live frame).
+#
+#   bash tests/screenshot.sh res://tests/_crafter_preview.tscn /tmp/out.png 20
+
+# Each cell is either a building type (drawn once) or a crafter phase.
+const CELLS: Array = [
+	{"type": "mothership"},
+	{"type": "command_center"},
+	{"type": "mothership"},
+	{"phase": 0.10},
+	{"phase": 0.35},
+	{"phase": 0.60},
+	{"phase": 0.88},
+]
+
+
+func _ready() -> void:
+	RenderingServer.set_default_clear_color(Color(0.02, 0.03, 0.06))
+	var building_scene: PackedScene = load("res://Building.tscn")
+	for i in range(CELLS.size()):
+		var cell: Dictionary = CELLS[i]
+		var b: Node2D = building_scene.instantiate()
+		b.building_type = cell.get("type", GameState.BUILDING_SHIP_CRAFTER)
+		b.position = Vector2(-240.0 + float(i % 3) * 240.0, -105.0 + float(i / 3) * 215.0)
+		add_child(b)
+		if cell.has("phase"):
+			b.set_process(false)
+			b.anim_time = float(cell.phase) * b.CYCLE
+			b.queue_redraw()
+
+	var cam: Camera2D = Camera2D.new()
+	cam.zoom = Vector2(1.65, 1.65)
+	add_child(cam)
+	cam.make_current()