chore(backend): 放宽递归与循环检测阈值

- build_run_config recursion_limit 100 -> 250
- LoopDetectionMiddleware 默认阈值放宽（warn/hard/window/tool-freq）

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

offline-backend-20260512/backend/app/gateway/services.py

@@ -314,7 +314,7 @@ def build_run_config(
     the LangGraph Platform-compatible HTTP API and the IM channel path behave
     identically.
     """
-    config: dict[str, Any] = {"recursion_limit": 100}
+    config: dict[str, Any] = {"recursion_limit": 250}
     if request_config:
         # LangGraph >= 0.6.0 introduced ``context`` as the preferred way to
         # pass thread-level data and rejects requests that include both

offline-backend-20260512/backend/packages/harness/deerflow/agents/middlewares/loop_detection_middleware.py

@@ -28,12 +28,12 @@ from langgraph.runtime import Runtime
 logger = logging.getLogger(__name__)
 
 # Defaults — can be overridden via constructor
-_DEFAULT_WARN_THRESHOLD = 3  # inject warning after 3 identical calls
-_DEFAULT_HARD_LIMIT = 5  # force-stop after 5 identical calls
-_DEFAULT_WINDOW_SIZE = 20  # track last N tool calls
+_DEFAULT_WARN_THRESHOLD = 8  # inject warning after 8 identical calls
+_DEFAULT_HARD_LIMIT = 20  # force-stop after 20 identical calls
+_DEFAULT_WINDOW_SIZE = 60  # track last N tool calls (must be >= hard_limit)
 _DEFAULT_MAX_TRACKED_THREADS = 100  # LRU eviction limit
-_DEFAULT_TOOL_FREQ_WARN = 30  # warn after 30 calls to the same tool type
-_DEFAULT_TOOL_FREQ_HARD_LIMIT = 50  # force-stop after 50 calls to the same tool type
+_DEFAULT_TOOL_FREQ_WARN = 80  # warn after 80 calls to the same tool type
+_DEFAULT_TOOL_FREQ_HARD_LIMIT = 120  # force-stop after 120 calls to the same tool type
 
 
 def _normalize_tool_call_args(raw_args: object) -> tuple[dict, str | None]:
@@ -142,19 +142,19 @@ class LoopDetectionMiddleware(AgentMiddleware[AgentState]):
 
     Args:
         warn_threshold: Number of identical tool call sets before injecting
-            a warning message. Default: 3.
+            a warning message. Default: 8.
         hard_limit: Number of identical tool call sets before stripping
-            tool_calls entirely. Default: 5.
+            tool_calls entirely. Default: 20.
         window_size: Size of the sliding window for tracking calls.
-            Default: 20.
+            Default: 60.
         max_tracked_threads: Maximum number of threads to track before
             evicting the least recently used. Default: 100.
         tool_freq_warn: Number of calls to the same tool *type* (regardless
             of arguments) before injecting a frequency warning. Catches
             cross-file read loops that hash-based detection misses.
-            Default: 30.
+            Default: 80.
         tool_freq_hard_limit: Number of calls to the same tool type before
-            forcing a stop. Default: 50.
+            forcing a stop. Default: 120.
     """
 
     def __init__(