fix: emoji column alignment + remove '· exit 0' from success output

- Add unicode-width crate, emoji_cell() pads 1-wide symbols (ℹ, ☀) to 2 cols
- All action/status cells now occupy exactly 2 terminal display columns
- exec success: show only first output line, no trailing '· exit 0'

crates/client/src/main.rs

@@ -25,7 +25,7 @@ use display::trunc;
 
 fn banner() {
     println!();
-    println!("  {}  HELIOS REMOTE  ({})", "☀".yellow().bold(), env!("GIT_COMMIT"));
+    println!("  {}   HELIOS REMOTE  ({})", "☀".yellow().bold(), env!("GIT_COMMIT"));
     #[cfg(windows)]
     {
         let admin = is_admin();
@@ -391,10 +391,8 @@ async fn handle_message(
                         } else {
                             format!("{first_line}  ·  exit {exit_code}")
                         }
-                    } else if first_line.is_empty() {
-                        "exit 0".to_string()
                     } else {
-                        format!("{first_line}  ·  exit 0")
+                        first_line  // success: just the output, no "exit 0"
                     };
                     display::cmd_done("⚡", "exec", &payload, exit_code == 0, &result);
                     let _ = stderr;