refactor(settings): 统一语言设置，合并 interface_language 和 ai_language

- 后端 Schema 将 interface_language 和 ai_language 合并为 language
- 前端设置界面只保留一个语言选项
- AI 回复语言统一使用 language 设置
- 更新协议文档
- 新增数据库迁移脚本

backend/src/core/agentscope/prompts/agent_prompt.py

@@ -12,10 +12,10 @@ def build_agent_prompt(
     *,
     agent_type: AgentType,
     llm_config: SystemAgentLLMConfig | None = None,
-    ai_language: str = "zh-CN",
+    language: str = "zh-CN",
 ) -> str:
     _ = agent_type, llm_config
-    role_playing = get_worker_role_playing(ai_language)
-    output_rules = get_worker_output_rules(ai_language)
+    role_playing = get_worker_role_playing(language)
+    output_rules = get_worker_output_rules(language)
     content = f"[role_playing]\n{role_playing}\n\n[output_json_rules]\n{output_rules}"
     return wrap_section("agent", content)

backend/src/core/agentscope/prompts/system_prompt.py

@@ -39,8 +39,8 @@ def _build_safety_section() -> str:
     )
 
 
-def _build_output_rules(*, ai_language: str) -> str:
-    lang_label = _get_language_label(ai_language)
+def _build_output_rules(*, language: str) -> str:
+    lang_label = _get_language_label(language)
     rules = [
         "[Language Requirement]",
         f"- You MUST respond in {lang_label}.",
@@ -68,7 +68,7 @@ def _build_time_context(*, now_utc: datetime | None) -> str:
 def build_system_prompt(
     *,
     agent_type: AgentType,
-    ai_language: str,
+    language: str,
     llm_config: SystemAgentLLMConfig | None = None,
     tools: Sequence[Tool | dict[str, Any]] | None = None,
     now_utc: datetime | None = None,
@@ -79,9 +79,9 @@ def build_system_prompt(
         build_agent_prompt(
             agent_type=agent_type,
             llm_config=llm_config,
-            ai_language=ai_language,
+            language=language,
         ),
         build_tools_prompt(tools=tools) if tools else None,
-        _build_output_rules(ai_language=ai_language),
+        _build_output_rules(language=language),
     ]
     return "\n\n".join(item for item in sections if item).strip()

backend/src/core/agentscope/prompts/worker_rules.py

@@ -101,14 +101,14 @@ answer: A complete reading covering overall judgment, current situation, final t
 sign_level: Must be exactly one of: 上上签 / 中上签 / 中下签 / 下下签. Always use the Chinese enum value regardless of language."""
 
 
-def get_worker_role_playing(ai_language: str) -> str:
-    _ = ai_language
+def get_worker_role_playing(language: str) -> str:
+    _ = language
     return _WORKER_ROLE_PLAYING
 
 
-def get_worker_output_rules(ai_language: str) -> str:
-    if ai_language.startswith("en"):
+def get_worker_output_rules(language: str) -> str:
+    if language.startswith("en"):
         return _WORKER_OUTPUT_RULES_EN
-    if ai_language.startswith("zh-Hant") or ai_language.startswith("zh_Hant"):
+    if language.startswith("zh-Hant") or language.startswith("zh_Hant"):
         return _WORKER_OUTPUT_RULES_ZH_HANT
     return _WORKER_OUTPUT_RULES_ZH_CN

backend/src/core/agentscope/runtime/runner.py

@@ -265,15 +265,15 @@ class AgentScopeRunner:
             emit_text_events=True,
             emit_tool_events=False,
         )
-        ai_language = "zh-CN"
+        language = "zh-CN"
         if user_context.settings is not None:
             prefs = getattr(user_context.settings, "preferences", None)
             if prefs is not None:
-                ai_language = getattr(prefs, "ai_language", "zh-CN") or "zh-CN"
+                language = getattr(prefs, "language", "zh-CN") or "zh-CN"
 
         system_prompt = build_system_prompt(
             agent_type=stage_config.agent_type,
-            ai_language=ai_language,
+            language=language,
             llm_config=stage_config.llm_config,
             tools=None,
             now_utc=datetime.now(timezone.utc),

backend/src/schemas/shared/user.py

@@ -11,12 +11,10 @@ _COUNTRY_PATTERN = re.compile(r"^[A-Z]{2}$")
 
 
 class PreferenceSettings(BaseModel):
-    interface_language: str = "zh-CN"
-    ai_language: str = "zh-CN"
+    language: str = "zh-CN"
     timezone: str = "Asia/Shanghai"
-    country: str = "US"
 
-    @field_validator("interface_language", "ai_language")
+    @field_validator("language")
     @classmethod
     def validate_language(cls, value: str) -> str:
         if not _BCP47_PATTERN.fullmatch(value):
@@ -32,14 +30,6 @@ class PreferenceSettings(BaseModel):
             raise ValueError("timezone must be a valid IANA timezone") from exc
         return value
 
-    @field_validator("country")
-    @classmethod
-    def validate_country(cls, value: str) -> str:
-        normalized = value.upper()
-        if not _COUNTRY_PATTERN.fullmatch(normalized):
-            raise ValueError("country must be an ISO 3166-1 alpha-2 code")
-        return normalized
-
 
 class NotificationSettings(BaseModel):
     allow_notifications: bool = True