feat: scaffold Readarr support across the state, app, handler, UI, and CLI layers

Promote Route::Readarr from a unit stub to a tuple variant and wire Readarr
through every layer, mirroring the Lidarr tree. Readarr appears as a fourth
servarr tab and its library view renders the Authors table.

Adds ReadarrData and its modals, the tick and context clue modules, the
top-level ReadarrHandler, ReadarrUi with the Authors library view, and an
empty ReadarrCommand behind ReadarrCliHandler. The default port is 8787.

Promoting the route variant compiles cleanly without any of the arms that
give it behaviour, so all six of those sites are wired explicitly here:
App::on_tick, handlers::handle_events, handle_prompt_toggle,
ServarrContextClueProvider, ui(), and verify_config_present_for_cli. Each was
checked by removing the arm and confirming its covering assertion then fails.

ReadarrEvent and ReadarrCommand are both declared empty. They gain variants
alongside the network calls and CLI commands that use them, which keeps each
later change to a single function.

Adding the tab changes the rendered tab bar, so 13 existing snapshots
regenerate. The only delta in each is that single tab bar line.

This scaffold adds 24 dead_code warnings, all inside the Readarr tree and
none outside it. They clear as the handlers, UI, network events, and CLI
commands that consume these items land: block arrays awaiting their accepts
implementations and BlockSelectionState seeding, modal and state fields
awaiting their handlers, the CLI handler fields awaiting an inhabited command
enum, and the top-level handler fields awaiting sub-handlers. The count must
strictly decrease from here, so a later increase is a defect rather than
transient noise. The 12 pre-existing collapsible_match warnings are unrelated
and untouched.

src/cli/mod.rs

@@ -6,6 +6,7 @@ use clap_complete::Shell;
 use indoc::indoc;
 use lidarr::{LidarrCliHandler, LidarrCommand};
 use radarr::{RadarrCliHandler, RadarrCommand};
+use readarr::{ReadarrCliHandler, ReadarrCommand};
 use sonarr::{SonarrCliHandler, SonarrCommand};
 use tokio::sync::Mutex;
 
@@ -13,6 +14,7 @@ use crate::{app::App, network::NetworkTrait};
 
 pub mod lidarr;
 pub mod radarr;
+pub mod readarr;
 pub mod sonarr;
 
 #[cfg(test)]
@@ -30,6 +32,9 @@ pub enum Command {
   #[command(subcommand, about = "Commands for manging your Lidarr instance")]
   Lidarr(LidarrCommand),
 
+  #[command(subcommand, about = "Commands for managing your Readarr instance")]
+  Readarr(ReadarrCommand),
+
   #[command(
     arg_required_else_help = true,
     about = "Generate shell completions for the Managarr CLI"
@@ -78,6 +83,11 @@ pub(crate) async fn handle_command(
         .handle()
         .await?
     }
+    Command::Readarr(readarr_command) => {
+      ReadarrCliHandler::with(app, readarr_command, network)
+        .handle()
+        .await?
+    }
     _ => String::new(),
   };
 

src/cli/readarr/mod.rs

@@ -0,0 +1,45 @@
+use std::sync::Arc;
+
+use anyhow::Result;
+use clap::Subcommand;
+use tokio::sync::Mutex;
+
+use super::{CliCommandHandler, Command};
+use crate::{app::App, network::NetworkTrait};
+
+#[cfg(test)]
+#[path = "readarr_command_tests.rs"]
+mod readarr_command_tests;
+
+#[derive(Debug, Clone, PartialEq, Eq, Subcommand)]
+pub enum ReadarrCommand {}
+
+impl From<ReadarrCommand> for Command {
+  fn from(readarr_command: ReadarrCommand) -> Command {
+    Command::Readarr(readarr_command)
+  }
+}
+
+pub(super) struct ReadarrCliHandler<'a, 'b> {
+  app: &'a Arc<Mutex<App<'b>>>,
+  command: ReadarrCommand,
+  network: &'a mut dyn NetworkTrait,
+}
+
+impl<'a, 'b> CliCommandHandler<'a, 'b, ReadarrCommand> for ReadarrCliHandler<'a, 'b> {
+  fn with(
+    app: &'a Arc<Mutex<App<'b>>>,
+    command: ReadarrCommand,
+    network: &'a mut dyn NetworkTrait,
+  ) -> Self {
+    ReadarrCliHandler {
+      app,
+      command,
+      network,
+    }
+  }
+
+  async fn handle(self) -> Result<String> {
+    match self.command {}
+  }
+}

src/cli/readarr/readarr_command_tests.rs

@@ -0,0 +1,15 @@
+#[cfg(test)]
+mod tests {
+  mod cli {
+    use clap::CommandFactory;
+
+    use crate::Cli;
+
+    #[test]
+    fn test_readarr_command_requires_a_subcommand() {
+      let result = Cli::command().try_get_matches_from(["managarr", "readarr"]);
+
+      assert_err!(&result);
+    }
+  }
+}