fix: stabilize Router model error handling

apps/web/vue3/main.py

@@ -62,12 +62,23 @@ DEFAULT_AGENT_LANG = "zh"
 if PLANTAI_RAG_ROOT.exists() and str(PLANTAI_RAG_ROOT) not in sys.path:
     sys.path.insert(0, str(PLANTAI_RAG_ROOT))
 
+_deepseek_api_key_before_rag_import = os.environ.get("DEEPSEEK_API_KEY")
+_plantai_new_api_bundle_configured = all(
+    str(os.environ.get(name) or "").strip()
+    for name in ("NEW_API_KEY", "NEW_API_BASE_URL", "NEW_API_MODEL")
+)
 try:
     from src.rag.unified.bbav5_methodology_config import build_bbav5_methodology_config
     METHODOLOGY_CONFIG_AVAILABLE = True
 except Exception as e:
     METHODOLOGY_CONFIG_AVAILABLE = False
     print(f"⚠️ 方法学配置模块加载失败: {e}")
+finally:
+    if _plantai_new_api_bundle_configured:
+        if _deepseek_api_key_before_rag_import is None:
+            os.environ.pop("DEEPSEEK_API_KEY", None)
+        else:
+            os.environ["DEEPSEEK_API_KEY"] = _deepseek_api_key_before_rag_import
 
 try:
     from gfa_core.mas.agents.interpretation_evidence import build_evidence_report