Fix CLI crash in non-TTY environments (fixes #122) (#123)

Guard interactive mode behind `isInteractive` flag
(`!options.ci && process.stdout.isTTY && process.stdin.isTTY`),
which also unifies the CI path and the non-TTY auto-detection into
a single branch. In non-interactive mode, live progress renders are
suppressed and the final result tree is printed once before exiting
with the correct code.

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: DmitrySharabin

src/env/node.js

@@ -129,18 +129,21 @@ export default {
 		process.env.NODE_ENV = "test";
 	},
 	done (result, options, event, root) {
-		if (options.ci) {
+		// Interactive mode requires both a TTY stdout (for cursor control) and a TTY stdin (for raw keypress events).
+		// The --ci flag explicitly opts into non-interactive mode regardless of TTY state.
+		let isInteractive = !options.ci && process.stdout.isTTY && process.stdin.isTTY;
+
+		if (!isInteractive) {
 			if (root.stats.pending === 0) {
 				if (root.stats.fail > 0 || options.verbose) {
 					let messages = root.toString(options);
 					let tree = getTree(messages).toString();
 					tree = format(tree);
 
 					console[root.stats.fail > 0 ? "error" : "log"](tree);
-					process.exit(root.stats.fail > 0 ? 1 : 0);
 				}
 
-				process.exit(0);
+				process.exit(root.stats.fail > 0 ? 1 : 0);
 			}
 		}
 		else {