v0.2.14 : aide Nushell, themes de couleurs et cadres blancs

- Aide facon Nushell : help <cmd>, <cmd> -h/--help, help, help commands,
  help --find <texte>, help <agent> (fiche info) - sections Usage/Flags/
  Command Type/Parameters/Input-output/Examples avec couleurs
- Commande version : tableau Nushell (commit, build, rustc, theme...) + --json ;
  build.rs pour commit/branche git ; -V reste la version courte
- Themes : --theme <nom> (default, ocean, sunset, forest, dracula, mono)
  + settings.theme dans la config ; activation VT Windows pour les couleurs
- Cadres blancs Nushell partages : list, search, status, doctor, ls/ps/
  where/get et menu d autocompletion Tab encadre (colonnes name/description)

src/cli.rs

@@ -10,6 +10,9 @@ use std::path::PathBuf;
     name = "am",
     bin_name = "am",
     version,
+    // The help subcommand is provided by the custom Nushell-style help
+    // (cli::Command::Help) instead of clap's generated one.
+    disable_help_subcommand = true,
     about = "agent-manager (am) — manage local AI coding agents",
     long_about = "agent-manager (am) — a CLI to manage local AI coding agents.
 
@@ -47,6 +50,10 @@ pub struct Cli {
     #[arg(long, global = true, action = ArgAction::SetTrue)]
     pub no_color: bool,
 
+    /// Color theme for the output: default, ocean, sunset, forest, dracula, mono
+    #[arg(long, global = true, value_name = "THEME")]
+    pub theme: Option<String>,
+
     #[command(subcommand)]
     pub command: Option<Command>,
 }
@@ -131,6 +138,16 @@ pub enum Command {
         /// Agent name or alias
         agent: String,
     },
+    /// Display help: the overview, a command, the command list, or a search
+    Help {
+        /// Command name (also accepts an agent name or alias); "commands" lists every command
+        command: Option<String>,
+        /// Search through all help commands table
+        #[arg(long, value_name = "TEXT")]
+        find: Option<String>,
+    },
+    /// Display version and build information
+    Version,
     /// Manage the configuration file
     #[command(subcommand)]
     Config(ConfigCmd),