feat(tauri): add single instance plugin and improve code formatting

This update introduces the tauri-plugin-single-instance to ensure that
only one instance of the application can run at a time. Additionally,
the code has been reformatted for better readability, with consistent
line breaks and spacing.

- Added single instance plugin to prevent multiple app instances
- Improved code formatting for better readability and maintenance
- Updated dependencies in Cargo.toml for new plugin integration

src-tauri/src/git.rs

@@ -681,7 +681,14 @@ pub fn create_tag(
         Some(message) => {
             run_git(
                 &repo,
-                ["tag", "-a", name.as_str(), "-m", message.as_str(), target.as_str()],
+                [
+                    "tag",
+                    "-a",
+                    name.as_str(),
+                    "-m",
+                    message.as_str(),
+                    target.as_str(),
+                ],
             )?;
         }
         None => {
@@ -755,7 +762,11 @@ fn validate_existing_tag_name(repo: &Path, name: &str) -> Result<String, String>
 
 fn validate_tag_ref_name(name: &str) -> Result<String, String> {
     let output = git_command()
-        .args(["check-ref-format", "--allow-onelevel", &format!("refs/tags/{name}")])
+        .args([
+            "check-ref-format",
+            "--allow-onelevel",
+            &format!("refs/tags/{name}"),
+        ])
         .output()
         .map_err(|err| format!("Could not start Git. Is Git installed? {err}"))?;
 
@@ -1096,7 +1107,11 @@ pub fn last_commit_message(path: String) -> Result<Option<String>, String> {
 
     let output = run_git(&repo, ["log", "-1", "--format=%B", "HEAD"])?;
     let message = String::from_utf8_lossy(&output).trim_end().to_string();
-    Ok(if message.is_empty() { None } else { Some(message) })
+    Ok(if message.is_empty() {
+        None
+    } else {
+        Some(message)
+    })
 }
 
 #[tauri::command]
@@ -5544,7 +5559,8 @@ mod tests {
     fn get_file_blame_attributes_lines_to_the_commits_that_introduced_them() {
         let repo = init_temp_repo("file_blame");
         commit_initial_file(&repo.path);
-        fs::write(repo.path.join("old.txt"), "original\ntwo\n").expect("tracked file should change");
+        fs::write(repo.path.join("old.txt"), "original\ntwo\n")
+            .expect("tracked file should change");
         run_git_test(&repo.path, ["add", "old.txt"]);
         run_git_test(&repo.path, ["commit", "-q", "-m", "add second line"]);