Suppress console windows on Windows and use ~/.paseo as default home

Add CREATE_NO_WINDOW flag to all Windows process spawns to prevent
visible console windows. Change Windows default managed home from
AppData\Roaming to ~/.paseo for consistency with macOS and server.

packages/desktop/src-tauri/src/lib.rs

@@ -229,8 +229,10 @@ fn shell_command(script: &str) -> Command {
     }
     #[cfg(windows)]
     {
+        use std::os::windows::process::CommandExt;
         let mut cmd = Command::new("cmd.exe");
         cmd.arg("/C").arg(script);
+        cmd.creation_flags(0x08000000); // CREATE_NO_WINDOW
         cmd
     }
 }