feat: v1.0 — am ask : langage naturel → commande am, règles locales FR/EN hors-ligne, raffinement LLM optionnel via le registre providers (token keyring, jamais de données du journal), cache des traductions, confirmation avant exécution, désactivable (closes #78)

- src/ask.rs : traducteur par règles (verbes FR/EN, pronoms, nicknames d'agents, séquences «et/puis»), cache ask_cache.json, POST /chat/completions du provider résolu avec Bearer du keyring, validation des commandes retournées, dégradation silencieuse sans token
- settings.ask {enabled (défaut true), provider, model} + doc config.yaml ; CLI/REPL/help/man/i18n
- 7 tests : règles (installe claude et lance-le → 2 commandes), cache, LLM via serveur tiny_http (token Bearer, zéro donnée du journal), dégradation, désactivation

src/config.rs

@@ -140,6 +140,11 @@ pub struct Settings {
     /// Nothing is collected or sent while `enabled` is false (the default).
     #[serde(default)]
     pub telemetry: Option<TelemetrySettings>,
+    /// am ask (issue #78): natural language → am command. The local rules
+    /// are always available; the optional LLM refinement uses the provider
+    /// registry. `enabled: false` turns the whole command off.
+    #[serde(default)]
+    pub ask: Option<AskSettings>,
     /// Plugin scripts (issue #75): default timeout and enable list.
     #[serde(default)]
     pub plugins: Option<PluginSettings>,
@@ -167,6 +172,30 @@ pub struct TelemetrySettings {
     pub endpoint: Option<String>,
 }
 
+/// am ask settings (issue #78): the LLM refinement is optional — without a
+/// provider, the local rule-based translator still works, offline.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(default)]
+pub struct AskSettings {
+    /// Master switch; false disables `am ask` entirely (issue #78).
+    pub enabled: bool,
+    /// Provider of the registry used for the refinement call. Falls back
+    /// to settings.default_provider when unset. None = rules only.
+    pub provider: Option<String>,
+    /// Model for the refinement call. Falls back to the provider default.
+    pub model: Option<String>,
+}
+
+impl Default for AskSettings {
+    fn default() -> Self {
+        AskSettings {
+            enabled: true,
+            provider: None,
+            model: None,
+        }
+    }
+}
+
 /// One entry of the LLM provider registry (issue #88).
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
 #[serde(deny_unknown_fields)]
@@ -872,6 +901,9 @@ pub fn merge(base: &mut Config, overlay: Config) {
     if o.telemetry.is_some() {
         s.telemetry = o.telemetry;
     }
+    if o.ask.is_some() {
+        s.ask = o.ask;
+    }
     if o.plugins.is_some() {
         s.plugins = o.plugins;
     }