refactor(main): Enforce root-only execution with fail-fast logic

Refactor the application's startup sequence to enforce a strict root-only requirement, removing the previous non-root fallback behavior.

The new logic in main() is as follows:
- On startup, check if the effective UID is 0.
- If not root, check for the availability of an 'su' binary.
- If 'su' is present, attempt self-elevation via `try_elevate_privileges()`. If this function returns (i.e., fails), exit the app with an error.
- If 'su' is not present, exit immediately with an error.

This change ensures that the application will not proceed to the TUI unless it has successfully acquired root privileges, preventing it from running in an unsupported and non-functional state.

Author: HanSoBored

src/main.rs

@@ -41,12 +41,25 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     log_info!("Android Ver: {}", device_info.android_ver);
     log_info!("Is Root: {}, Can SU: {}", device_info.is_root, device_info.can_su);
 
-    if !device_info.is_root && device_info.can_su {
-        log_info!("Attempting self-elevation...");
-        try_elevate_privileges();
-        log_info!("Failed to elevate. Continuing as non-root (PRoot mode only).");
+    if !device_info.is_root {
+        if device_info.can_su {
+            log_info!("Not root. Attempting self-elevation...");
+            try_elevate_privileges();
+
+            let err_msg = "Failed to gain root access. Please grant permission to the 'su' request.";
+            log_error!("{}", err_msg);
+            eprintln!("{}", err_msg);
+            exit(1);
+        } else {
+            let err_msg = "Root access is required, but 'su' binary not found.";
+            log_error!("{}", err_msg);
+            eprintln!("{}", err_msg);
+            exit(1);
+        }
     }
 
+    log_info!("Root access confirmed. Initializing TUI...");
+
     enable_raw_mode()?;
     let mut stdout = io::stdout();
     execute!(stdout, EnterAlternateScreen)?;