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/run_tests.sh

@@ -0,0 +1,20 @@
+#!/data/data/com.termux/files/usr/bin/bash
+# Runs the headless GDScript gameplay tests from Termux, via the Godot
+# 4.7.1 Linux arm64 build installed inside the proot-distro Ubuntu container.
+# Usage: bash tests/run_tests.sh
+
+set -e
+PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+GODOT_BIN="/root/Godot_v4.7.1-stable_linux.arm64"
+
+status=0
+for test_script in "$PROJECT_DIR"/tests/test_*.gd; do
+  name="$(basename "$test_script")"
+  echo "=== Running $name ==="
+  if ! proot-distro login ubuntu -- bash -c "cd '$PROJECT_DIR' && '$GODOT_BIN' --headless -s res://tests/$name"; then
+    status=1
+  fi
+  echo
+done
+
+exit $status