Add -V/--version flag

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GLUwWE2KmFPzhKaf67tWbx

src/main.rs

@@ -22,6 +22,7 @@ Options:
     --midi-name <s>   Connect to the MIDI output port whose name contains <s>
                       instead of creating a virtual port
     --list-midi       List available MIDI output ports and exit
+    -V, --version     Print version and exit
     -h, --help        Print this message and exit
 
 A default MIDI port can be set in ~/.config/orca-rs/config.toml:
@@ -77,6 +78,10 @@ fn main() {
                 }
                 return;
             }
+            "-V" | "--version" => {
+                println!("orca-rs {}", env!("CARGO_PKG_VERSION"));
+                return;
+            }
             "-h" | "--help" => {
                 print!("{USAGE}");
                 return;