[router] update generate spec to align with sgl io struct (#11591)

sgl-router/src/routers/grpc/pipeline.rs

@@ -877,7 +877,7 @@ impl ResponseProcessingStage {
         }
 
         // Non-streaming: Delegate to ResponseProcessor
-        let request_logprobs = ctx.generate_request().return_logprob;
+        let request_logprobs = ctx.generate_request().return_logprob.unwrap_or(false);
         let generate_request = ctx.generate_request_arc();
 
         let stop_decoder = ctx

sgl-router/src/routers/grpc/streaming.rs

@@ -616,7 +616,7 @@ impl StreamingProcessor {
         generate_request: Arc<GenerateRequest>,
         dispatch: context::DispatchMetadata,
     ) -> Response {
-        let return_logprob = generate_request.return_logprob;
+        let return_logprob = generate_request.return_logprob.unwrap_or(false);
 
         // Create SSE channel
         let (tx, rx) = mpsc::unbounded_channel::<Result<Bytes, io::Error>>();

sgl-router/src/routers/http/pd_router.rs

@@ -150,11 +150,6 @@ impl PDRouter {
     }
 
     fn get_generate_batch_size(req: &GenerateRequest) -> Option<usize> {
-        if let Some(StringOrArray::Array(arr)) = &req.prompt {
-            if !arr.is_empty() {
-                return Some(arr.len());
-            }
-        }
         if let Some(text) = &req.text {
             if text.contains("[") && text.contains("]") {
                 return None;
@@ -1061,18 +1056,10 @@ impl RouterTrait for PDRouter {
         model_id: Option<&str>,
     ) -> Response {
         let is_stream = body.stream;
-        let return_logprob = body.return_logprob;
+        let return_logprob = body.return_logprob.unwrap_or(false);
 
         let request_text = if self.policies_need_request_text() {
-            body.text
-                .as_deref()
-                .or_else(|| {
-                    body.prompt.as_ref().and_then(|p| match p {
-                        StringOrArray::String(s) => Some(s.as_str()),
-                        StringOrArray::Array(v) => v.first().map(|s| s.as_str()),
-                    })
-                })
-                .map(|s| s.to_string())
+            body.text.as_deref().map(|s| s.to_string())
         } else {
             None
         };