Add support for multi-character flag aliases and enhance argument handling

- Introduced `MULTI_CHAR_ALIASES` for mapping long flag names to multi-character short aliases.
- Updated argument normalization to preprocess multi-character short-form flags.
- Refactored help output to include alias visibility and improve alignment.
- Enhanced CLI flag definition capabilities with better support for optional boolean arguments.

src/cli.rs

@@ -71,12 +71,12 @@ pub struct EditArgs {
     pub name: String,
 
     /// Enable or disable the self-monitor loopback.
-    #[arg(short, long, value_name = "BOOL")]
+    #[arg(short, long, num_args = 0..=1, default_missing_value = "true", value_name = "BOOL")]
     pub loopback: Option<bool>,
 
     /// Keep a mixed-in source audible in the loopback instead of isolating
     /// it (2-node topology instead of 4).
-    #[arg(long = "loopback-no-mix", value_name = "BOOL")]
+    #[arg(long = "loopback-no-mix", num_args = 0..=1, default_missing_value = "true", value_name = "BOOL")]
     pub loopback_no_mix: Option<bool>,
 
     /// Loopback volume: fraction (0.8) or percent (80).
@@ -84,7 +84,7 @@ pub struct EditArgs {
     pub volume: Option<f32>,
 
     /// Mixed-in source volume: fraction (0.8) or percent (80).
-    #[arg(long = "source-volume", visible_alias = "sv", value_name = "PCT")]
+    #[arg(long = "source-volume", value_name = "PCT")]
     pub source_volume: Option<f32>,
 }