refactor(coding-agent): centralize git url detection

packages/coding-agent/src/utils/git.ts

@@ -0,0 +1,6 @@
+const GIT_HOSTS = ["github.com", "gitlab.com", "bitbucket.org", "codeberg.org"];
+
+export function looksLikeGitUrl(source: string): boolean {
+	const normalized = source.replace(/^https?:\/\//, "");
+	return GIT_HOSTS.some((host) => normalized.startsWith(`${host}/`));
+}