feat(readarr): fetch Readarr disk space and expose it on the CLI

Add ReadarrEvent::GetDiskSpace, mapped to GET /diskspace, and
get_readarr_diskspace, which stores the result on ReadarrData for the
root folder and system views.

Surface it as `managarr readarr list disk-space`, matching the other
three servarrs.

Readarr returns a label field on some records that DiskSpace does not
model; serde drops it, so the CLI prints only the path and the free and
total space, as it does for the other three servarrs.

src/cli/readarr/list_command_handler.rs

@@ -0,0 +1,62 @@
+use std::sync::Arc;
+
+use anyhow::Result;
+use clap::Subcommand;
+use tokio::sync::Mutex;
+
+use super::ReadarrCommand;
+use crate::{
+  app::App,
+  cli::{CliCommandHandler, Command},
+  network::{NetworkTrait, readarr_network::ReadarrEvent},
+};
+
+#[cfg(test)]
+#[path = "list_command_handler_tests.rs"]
+mod list_command_handler_tests;
+
+#[derive(Debug, Clone, PartialEq, Eq, Subcommand)]
+pub enum ReadarrListCommand {
+  #[command(about = "List disk space details for all provisioned root folders in Readarr")]
+  DiskSpace,
+}
+
+impl From<ReadarrListCommand> for Command {
+  fn from(value: ReadarrListCommand) -> Self {
+    Command::Readarr(ReadarrCommand::List(value))
+  }
+}
+
+pub(super) struct ReadarrListCommandHandler<'a, 'b> {
+  _app: &'a Arc<Mutex<App<'b>>>,
+  command: ReadarrListCommand,
+  network: &'a mut dyn NetworkTrait,
+}
+
+impl<'a, 'b> CliCommandHandler<'a, 'b, ReadarrListCommand> for ReadarrListCommandHandler<'a, 'b> {
+  fn with(
+    _app: &'a Arc<Mutex<App<'b>>>,
+    command: ReadarrListCommand,
+    network: &'a mut dyn NetworkTrait,
+  ) -> Self {
+    ReadarrListCommandHandler {
+      _app,
+      command,
+      network,
+    }
+  }
+
+  async fn handle(self) -> Result<String> {
+    let result = match self.command {
+      ReadarrListCommand::DiskSpace => {
+        let resp = self
+          .network
+          .handle_network_event(ReadarrEvent::GetDiskSpace.into())
+          .await?;
+        serde_json::to_string_pretty(&resp)?
+      }
+    };
+
+    Ok(result)
+  }
+}

src/cli/readarr/list_command_handler_tests.rs

@@ -0,0 +1,73 @@
+#[cfg(test)]
+mod tests {
+  use crate::Cli;
+  use crate::cli::{
+    Command,
+    readarr::{ReadarrCommand, list_command_handler::ReadarrListCommand},
+  };
+  use clap::CommandFactory;
+  use pretty_assertions::assert_eq;
+
+  #[test]
+  fn test_readarr_list_command_from() {
+    let command = ReadarrListCommand::DiskSpace;
+
+    let result = Command::from(command.clone());
+
+    assert_eq!(result, Command::Readarr(ReadarrCommand::List(command)));
+  }
+
+  mod cli {
+    use rstest::rstest;
+
+    use super::*;
+
+    #[rstest]
+    fn test_list_commands_have_no_arg_requirements(#[values("disk-space")] subcommand: &str) {
+      let result = Cli::command().try_get_matches_from(["managarr", "readarr", "list", subcommand]);
+
+      assert_ok!(&result);
+    }
+  }
+
+  mod handler {
+    use std::sync::Arc;
+
+    use mockall::predicate::eq;
+    use serde_json::json;
+    use tokio::sync::Mutex;
+
+    use crate::{
+      app::App,
+      cli::{
+        CliCommandHandler,
+        readarr::list_command_handler::{ReadarrListCommand, ReadarrListCommandHandler},
+      },
+      models::{Serdeable, readarr_models::ReadarrSerdeable},
+      network::{MockNetworkTrait, NetworkEvent, readarr_network::ReadarrEvent},
+    };
+
+    #[tokio::test]
+    async fn test_handle_list_disk_space_command() {
+      let mut mock_network = MockNetworkTrait::new();
+      mock_network
+        .expect_handle_network_event()
+        .with(eq::<NetworkEvent>(ReadarrEvent::GetDiskSpace.into()))
+        .times(1)
+        .returning(|_| {
+          Ok(Serdeable::Readarr(ReadarrSerdeable::Value(
+            json!({"testResponse": "response"}),
+          )))
+        });
+      let app_arc = Arc::new(Mutex::new(App::test_default()));
+      let list_disk_space_command = ReadarrListCommand::DiskSpace;
+
+      let result =
+        ReadarrListCommandHandler::with(&app_arc, list_disk_space_command, &mut mock_network)
+          .handle()
+          .await;
+
+      assert_ok!(&result);
+    }
+  }
+}

src/cli/readarr/mod.rs

@@ -3,12 +3,14 @@ use std::sync::Arc;
 use anyhow::Result;
 use clap::Subcommand;
 use get_command_handler::{ReadarrGetCommand, ReadarrGetCommandHandler};
+use list_command_handler::{ReadarrListCommand, ReadarrListCommandHandler};
 use tokio::sync::Mutex;
 
 use super::{CliCommandHandler, Command};
 use crate::{app::App, network::NetworkTrait};
 
 mod get_command_handler;
+mod list_command_handler;
 
 #[cfg(test)]
 #[path = "readarr_command_tests.rs"]
@@ -21,6 +23,11 @@ pub enum ReadarrCommand {
     about = "Commands to fetch details of the resources in your Readarr instance"
   )]
   Get(ReadarrGetCommand),
+  #[command(
+    subcommand,
+    about = "Commands to list attributes from your Readarr instance"
+  )]
+  List(ReadarrListCommand),
 }
 
 impl From<ReadarrCommand> for Command {
@@ -55,6 +62,11 @@ impl<'a, 'b> CliCommandHandler<'a, 'b, ReadarrCommand> for ReadarrCliHandler<'a,
           .handle()
           .await?
       }
+      ReadarrCommand::List(list_command) => {
+        ReadarrListCommandHandler::with(self.app, list_command, self.network)
+          .handle()
+          .await?
+      }
     };
 
     Ok(result)