feat: allow hook model overrides

src/gateway/server-http.ts

@@ -41,6 +41,7 @@ type HookDispatchers = {
       | "signal"
       | "imessage";
     to?: string;
+    model?: string;
     thinking?: string;
     timeoutSeconds?: number;
   }) => string;
@@ -177,6 +178,7 @@ export function createHooksRequestHandler(
             deliver: mapped.action.deliver === true,
             provider: mapped.action.provider ?? "last",
             to: mapped.action.to,
+            model: mapped.action.model,
             thinking: mapped.action.thinking,
             timeoutSeconds: mapped.action.timeoutSeconds,
           });