play.sh to start the game; Godot checks shared with run_server.sh

tools/godot_env.sh

@@ -0,0 +1,34 @@
+# Shared by play.sh and server/run_server.sh (sourced, not run). Run from the
+# project folder. Sets GODOT to a Godot 4.7+ binary and imports a fresh copy
+# of the project once; exits with a message if either isn't possible.
+#
+# Godot's class cache lives in .godot/, which isn't in git, so a new clone
+# can't run until it has been imported.
+
+GODOT="${GODOT:-godot}"
+if ! command -v "$GODOT" >/dev/null 2>&1; then
+	# macOS: use the app bundle if `godot` isn't on the PATH.
+	if [ -x /Applications/Godot.app/Contents/MacOS/Godot ]; then
+		GODOT=/Applications/Godot.app/Contents/MacOS/Godot
+	else
+		echo "Can't find Godot. Install 4.7.2 from https://godotengine.org/download, or set GODOT=/path/to/godot" >&2
+		exit 1
+	fi
+fi
+
+version=$("$GODOT" --version 2>/dev/null | tail -n 1)
+major=$(echo "$version" | cut -d. -f1)
+minor=$(echo "$version" | cut -d. -f2)
+if [ -z "$major" ] || [ "$major" -lt 4 ] || { [ "$major" -eq 4 ] && [ "$minor" -lt 7 ]; }; then
+	echo "This game needs Godot 4.7 or newer, but $GODOT is ${version:-unknown}." >&2
+	echo "Download 4.7.2 from https://godotengine.org/download (or set GODOT=/path/to/a/newer/godot)" >&2
+	exit 1
+fi
+
+if [ ! -f .godot/global_script_class_cache.cfg ]; then
+	echo "First run on this copy: importing the project (a few seconds)..."
+	if ! "$GODOT" --headless --path . --import >/dev/null 2>&1 || [ ! -f .godot/global_script_class_cache.cfg ]; then
+		echo "Import failed. Try: $GODOT --headless --path . --import" >&2
+		exit 1
+	fi
+fi