Add an assets list command

src/args.rs

@@ -27,6 +27,14 @@ pub(crate) struct Opts {
 
 #[derive(Serialize, Subcommand)]
 pub(crate) enum Commands {
+    /// Assets related commands
+    #[serde(rename = "assets")]
+    Assets {
+        #[command(subcommand)]
+        #[serde(flatten)]
+        assets_command: AssetsCommands,
+    },
+
     /// People related commands
     #[serde(rename = "people")]
     People {
@@ -43,6 +51,17 @@ pub(crate) enum Commands {
     },
 }
 
+#[derive(Serialize, Subcommand)]
+pub(crate) enum AssetsCommands {
+    /// List all assets
+    #[serde(rename = "list")]
+    List {
+        /// List only offline assets
+        #[arg(short, long, action)]
+        offline: bool,
+    },
+}
+
 #[derive(Serialize, Subcommand)]
 pub(crate) enum PeopleCommands {
     /// Synchronises date of births from a vcard file