Add --version/-v flag to CLI (#170)

- Parse --version and -v flags in args.ts
- Handle version flag early in main.ts (print and exit)
- Add flag to help text
- Add comprehensive test coverage for CLI arg parsing

Co-authored-by: cc-vps <crcatala+vps@gmail.com>

packages/coding-agent/src/main.ts

@@ -139,6 +139,11 @@ function prepareInitialMessage(parsed: Args): {
 export async function main(args: string[]) {
 	const parsed = parseArgs(args);
 
+	if (parsed.version) {
+		console.log(VERSION);
+		return;
+	}
+
 	if (parsed.help) {
 		printHelp();
 		return;