i18n: add embedding_api_base hint translations

Author: exynos967

dashboard/src/i18n/locales/en-US/features/config-metadata.json

@@ -1084,7 +1084,8 @@
         "description": "API Key"
       },
       "embedding_api_base": {
-        "description": "API Base URL"
+        "description": "API Base URL",
+        "hint": "OpenAI Embedding automatically appends /v1 at request time. For Gemini Embedding, use https://generativelanguage.googleapis.com and do not add /v1beta manually."
       },
       "volcengine_cluster": {
         "description": "Volcengine cluster",

dashboard/src/i18n/locales/zh-CN/features/config-metadata.json

@@ -1087,7 +1087,8 @@
         "description": "API Key"
       },
       "embedding_api_base": {
-        "description": "API Base URL"
+        "description": "API Base URL",
+        "hint": "OpenAI Embedding 会在请求时自动补上 /v1。Gemini Embedding 建议填写 https://generativelanguage.googleapis.com，无需手动添加 /v1beta。"
       },
       "volcengine_cluster": {
         "description": "火山引擎集群",