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/Cargo.toml

@@ -25,6 +25,7 @@ png = "0.17"
 futures-util = "0.3"
 colored = "2"
 terminal_size = "0.3"
+unicode-width = "0.1"
 
 [build-dependencies]
 winres = "0.1"