[OP][Feature] 统一 limit_thinking_content_length CUDA 算子，支持回复长度限制与注入序列 (#6493)

* Initial plan

* Migrate PRs #6311, #6129, #6305 to develop and merge unit tests

Co-authored-by: yuanlehome <23653004+yuanlehome@users.noreply.github.com>

* fix

* update

* fix

* fix ci

* fix ci

* Initial plan

* test: add test_chat_with_response_max_tokens to test_EB_VL_Lite_serving.py

Co-authored-by: yuanlehome <23653004+yuanlehome@users.noreply.github.com>

* test: add disable-thinking case to test_chat_with_response_max_tokens

Co-authored-by: yuanlehome <23653004+yuanlehome@users.noreply.github.com>

* test: add both reasoning_max_tokens and response_max_tokens case

Co-authored-by: yuanlehome <23653004+yuanlehome@users.noreply.github.com>

* fix ci

* fix ci

* fix ci

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: yuanlehome <23653004+yuanlehome@users.noreply.github.com>

fastdeploy/input/qwen_vl_processor/qwen_vl_processor.py

@@ -265,8 +265,11 @@ class QwenVLProcessor(TextProcessor):
             ]  # Leave space for at least 1 new token
 
         # Set default max_tokens if not specified
+        max_tokens = max_model_len - len(request["prompt_token_ids"])
         if request.get("max_tokens") is None:
-            request["max_tokens"] = max(1, max_model_len - len(request["prompt_token_ids"]))  # Ensure at least 1 token
+            request["max_tokens"] = max(1, max_tokens)
+        else:
+            request["max_tokens"] = min(max_tokens, request["max_tokens"])
         if self.reasoning_parser:
             model_status = self.reasoning_parser.get_model_status(request["prompt_token_ids"])
             parts = request["request_id"].split("_")