docs: add and clean up AI-generated rustdoc comments (grok-4.5)

src/utils/git.rs

@@ -1,6 +1,9 @@
 use std::path::Path;
 use std::process::Command;
 
+/// Checks if the `git` executable is available in the system's PATH.
+///
+/// This function executes `git --version` and returns `true` if the command succeeds, `false` otherwise.
 pub fn is_git_available() -> bool {
     Command::new("git")
         .arg("--version")
@@ -9,6 +12,7 @@ pub fn is_git_available() -> bool {
         .unwrap_or(false)
 }
 
+/// Initializes a new Git repository at the specified path.
 pub fn git_init(path: &Path) -> Result<(), String> {
     if !is_git_available() {
         return Err("git executable not found in PATH".to_string());