feat: phase 2 — modèles locaux + catalogue distant + suggest (closes #70 #71 #73 #60 #67 #61)

Axe 11 (modèles) :
- am models : inventaire des runtimes locaux (ollama list --format json,
  llama.cpp .gguf sur disque, LM Studio API locale) avec cache façon
  probe.rs (TTL 30s) et absence de runtime signalée sans erreur fatale
- am run <agent> --model <m> : résolution dans l'inventaire, transmission
  via model_env/model_arg de l'agent (défaut AM_MODEL), tracé en session
- am models --prune : candidats inutilisés depuis settings.models_prune_days
  (défaut 30), :latest toujours protégé, dry-run + confirmation + événement
  EventKind::Model journalisé

Axes 7/9 (catalogue) :
- am catalog update : fetch du catalogue officiel, diff (ajoutés/retirés/
  modifiés), confirmation, enregistrement en include
- am catalog add <url> : validation du format (parse + validate), cache
  catalog-cache.json (TTL 3600s), événement EventKind::Catalog journalisé
- include par URL (http/https/file) dans config.yaml, résolu au chargement
  avec cache + TTL ; override local toujours prioritaire (issue #67)
- am suggest <requête> : réutilise le scoring fuzzy du catalogue, boost par
  usage réel (lancements + durée depuis le journal), top 5 justifié, --json

REPL : commandes models/catalog/suggest (parse, complétion, descriptions),
help specs, tip cheat sheet, man pages régénérées (49 pages, dont 3 nouvelles).
Version bump 0.4.5, ROADMAP cases cochées, 266 tests verts.

src/cli.rs

@@ -175,6 +175,17 @@ pub enum Command {
     /// Manage secrets in the OS keyring (never in plaintext config)
     #[command(subcommand)]
     Secret(SecretCmd),
+    /// List local models (ollama, llama.cpp, LM Studio) and prune unused ones
+    Models(ModelsArgs),
+    /// Manage remote catalogs: update the official one, add external ones
+    #[command(subcommand)]
+    Catalog(CatalogCmd),
+    /// Suggest agents matching a query, boosted by real usage (issue #61)
+    Suggest {
+        /// Free-form request ("un agent pour du Python")
+        #[arg(value_name = "QUERY", num_args = 1.., required = true)]
+        words: Vec<String>,
+    },
     /// Start an agent (foreground by default, or detached with --background)
     Start(StartArgs),
     /// Stop a background agent (SIGTERM, then SIGKILL after the timeout)
@@ -387,6 +398,9 @@ pub enum Command {
     Run {
         /// Agent name or alias
         agent: String,
+        /// Local model to use for this run (validated against the local runtimes)
+        #[arg(long, value_name = "MODEL")]
+        model: Option<String>,
         /// Arguments passed through to the agent command
         #[arg(trailing_var_arg = true, allow_hyphen_values = true, value_name = "ARGS...")]
         args: Vec<std::ffi::OsString>,
@@ -452,6 +466,41 @@ pub struct StartArgs {
     /// Apply an environment profile (env + args, defined in the config)
     #[arg(long, value_name = "NAME")]
     pub profile: Option<String>,
+    /// Local model to use for this run (validated against the local runtimes)
+    #[arg(long, value_name = "MODEL")]
+    pub model: Option<String>,
+}
+
+/// Arguments of the models command: inventory by default, prune with --prune.
+#[derive(Args, Debug, Clone, Default)]
+pub struct ModelsArgs {
+    /// Purge unused models instead of listing them
+    #[arg(long)]
+    pub prune: bool,
+    /// Only list what would be pruned, delete nothing
+    #[arg(long, conflicts_with = "yes")]
+    pub dry_run: bool,
+    /// Answer yes to the deletion prompt
+    #[arg(long)]
+    pub yes: bool,
+    /// Consider a model unused after N days (default: 30)
+    #[arg(long, value_name = "DAYS")]
+    pub days: Option<u64>,
+}
+
+/// Remote catalog subcommands (issues #60 #67).
+#[derive(Subcommand, Debug, Clone)]
+pub enum CatalogCmd {
+    /// Fetch the official catalog, show the diff and register it as an include
+    Update,
+    /// Register an external catalog (same YAML format) by URL
+    Add {
+        /// Catalog URL (http, https or file)
+        #[arg(value_name = "URL")]
+        url: String,
+    },
+    /// List the registered remote catalogs
+    List,
 }
 
 /// Environment profile subcommands (issue #40).