feat(src): adddisplay management commands

Implement display command to query and set refresh rates.

New Features
- Add DisplayCommands with Rates and SetRate subcommands
- Register display command in CLI dispatcher

Enhancements
- Extend command dispatch to handle Display subcommand

Bug Fixes
- None

src/cli.rs

@@ -37,6 +37,11 @@ pub enum Commands {
         #[command(subcommand)]
         command: CoolingCommands,
     },
+    /// Display management commands
+    Display {
+        #[command(subcommand)]
+        command: DisplayCommands,
+    },
     /// Hardware status
     Status,
     /// Install udev rules for rootless operation
@@ -144,3 +149,14 @@ pub enum TouchpadCommands {
     /// Disable the touchpad
     Disable,
 }
+
+#[derive(Subcommand, Debug)]
+pub enum DisplayCommands {
+    /// Show available and active refresh rates
+    Rates,
+    /// Set the display refresh rate
+    SetRate {
+        /// Target refresh rate in Hz
+        rate: f32,
+    },
+}

src/main.rs

@@ -26,6 +26,7 @@ fn main() {
         Commands::Battery { command } => commands::battery::execute(command),
         Commands::Power { command } => commands::power::execute(command),
         Commands::Cooling { command } => commands::cooling::execute(command),
+        Commands::Display { command } => commands::display::execute(command),
         Commands::Status => commands::status::execute(),
         Commands::InstallRules => commands::install_rules::execute(),
         Commands::Touchpad { command } => commands::touchpad::execute(command),