fix: preserve parameter expansion (${VAR:-default}) in .env interpolation

apps/dokploy/__test__/compose/env-file-literals.test.ts

@@ -34,6 +34,7 @@ const cases: Record<string, string> = {
 	MULTILINE_PEM: "-----BEGIN KEY-----\nabc123\n-----END KEY-----",
 	APP_URL: "https://example.com",
 	ASSET_URL: "https://example.com",
+	DB_HOST: "localhost",
 };
 
 // How each value must be typed in the UI so the (unchanged) dotenv input
@@ -50,6 +51,7 @@ const inputEncoding: Record<string, string> = {
 	MULTILINE_PEM: '"-----BEGIN KEY-----\nabc123\n-----END KEY-----"',
 	APP_URL: "https://example.com",
 	ASSET_URL: '"${APP_URL}"',
+	DB_HOST: '"${UNDEFINED_HOST:-localhost}"',
 };
 
 describe("getCreateEnvFileCommand", () => {

packages/server/src/utils/docker/utils.ts

@@ -548,7 +548,7 @@ export const prepareEnvironmentVariablesForFile = (
 		const escapedValue = value
 			.replace(/\\/g, "\\\\")
 			.replace(/"/g, '\\"')
-			.replace(/\$(?!\{[A-Za-z_][A-Za-z0-9_]*\})/g, "\\$");
+			.replace(/\$(?!\{[A-Za-z_][A-Za-z0-9_]*(?::?[-+?][^{}]*)?\})/g, "\\$");
 		return `${key}="${escapedValue}"`;
 	});
 };