refactor(deps): replace git2 with system git and add vcs support

tests/cli_basic.rs

@@ -99,6 +99,60 @@ fn new_creates_project_layout() {
     );
 }
 
+fn is_git_in_path() -> bool {
+    std::process::Command::new("git")
+        .arg("--version")
+        .output()
+        .map(|o| o.status.success())
+        .unwrap_or(false)
+}
+
+#[test]
+fn new_vcs_options_work() {
+    // 1. Test --vcs none
+    let dir = unique_sandbox_dir("new_vcs_none");
+    let out = run_dcr(&["new", "hello_none", "--vcs", "none"], &dir);
+    assert!(out.status.success(), "dcr new --vcs none should succeed");
+    let project_dir = dir.join("hello_none");
+    assert!(project_dir.is_dir());
+    assert!(!project_dir.join(".git").exists());
+    assert!(!project_dir.join(".gitignore").exists());
+
+    // 2. Test --vcs git
+    if is_git_in_path() {
+        let dir = unique_sandbox_dir("new_vcs_git");
+        let out = run_dcr(&["new", "hello_git", "--vcs", "git"], &dir);
+        assert!(out.status.success(), "dcr new --vcs git should succeed");
+        let project_dir = dir.join("hello_git");
+        assert!(project_dir.is_dir());
+        assert!(project_dir.join(".git").is_dir());
+        assert!(project_dir.join(".gitignore").is_file());
+        let gitignore = std::fs::read_to_string(project_dir.join(".gitignore")).unwrap();
+        assert!(gitignore.contains("/target"));
+    }
+}
+
+#[test]
+fn init_vcs_options_work() {
+    // 1. Test --vcs none
+    let dir = unique_sandbox_dir("init_vcs_none");
+    let out = run_dcr(&["init", "--vcs", "none"], &dir);
+    assert!(out.status.success(), "dcr init --vcs none should succeed");
+    assert!(!dir.join(".git").exists());
+    assert!(!dir.join(".gitignore").exists());
+
+    // 2. Test --vcs git
+    if is_git_in_path() {
+        let dir = unique_sandbox_dir("init_vcs_git");
+        let out = run_dcr(&["init", "--vcs", "git"], &dir);
+        assert!(out.status.success(), "dcr init --vcs git should succeed");
+        assert!(dir.join(".git").is_dir());
+        assert!(dir.join(".gitignore").is_file());
+        let gitignore = std::fs::read_to_string(dir.join(".gitignore")).unwrap();
+        assert!(gitignore.contains("/target"));
+    }
+}
+
 #[test]
 fn init_and_clean_remove_target() {
     let dir = unique_sandbox_dir("init");