feat: prompt command (MessageBox), admin status in banner

crates/server/src/api.rs

@@ -479,6 +479,30 @@ pub async fn clipboard_set(
     }
 }
 
+/// POST /sessions/:id/prompt
+#[derive(Deserialize)]
+pub struct PromptBody {
+    pub message: String,
+    pub title: Option<String>,
+}
+
+pub async fn prompt_user(
+    Path(session_id): Path<String>,
+    State(state): State<AppState>,
+    Json(body): Json<PromptBody>,
+) -> impl IntoResponse {
+    match dispatch(&state, &session_id, "prompt", |rid| ServerMessage::PromptRequest {
+        request_id: rid,
+        message: body.message.clone(),
+        title: body.title.clone(),
+    })
+    .await
+    {
+        Ok(_) => (StatusCode::OK, Json(serde_json::json!({ "ok": true }))).into_response(),
+        Err(e) => e.into_response(),
+    }
+}
+
 /// POST /sessions/:id/label
 #[derive(Deserialize)]
 pub struct LabelBody {