feat: 添加视觉设计语言系统并重构认证页面UI

- 新增 visual_design_language.md 设计规范文档
- 新增 auth 设计 tokens (authBackground, authCard, authInput, feedback 系列等)
- 重构登录/注册/验证码/重置密码页面为新设计系统
- 新增 AuthHeroHeader, AuthSurfaceCard, AuthSection, AuthField, PasswordField 组件
- 重构 AppBanner 和 Toast 支持多类型配置 (info/success/warning/error)
- 后端 AgentScope: 重整 schemas/prompts/tools 作用域, 新增协议文档
- 更新 AGENTS.md 集成视觉设计语言约束

backend/src/services/base/supabase.py

@@ -6,6 +6,7 @@ from typing import Any
 from supabase import create_client
 
 from core.config.settings import SupabaseSettings, config
+from core.config.settings import config as app_config
 
 from .service_interface import BaseServiceProvider, register_service_instance
 
@@ -20,6 +21,7 @@ class SupabaseService(BaseServiceProvider):
     async def initialize(self, **_: Any) -> bool:
         try:
             self._init_clients()
+            await self._ensure_storage_bucket()
             self._set_initialized(True)
             self.logger.info("Supabase service initialized")
             return True
@@ -96,6 +98,47 @@ class SupabaseService(BaseServiceProvider):
             self._settings.service_role_key,
         )
 
+    async def _ensure_storage_bucket(self) -> None:
+        bucket_name = app_config.storage.bucket
+        storage = getattr(self._admin_client, "storage", None)
+        if storage is None:
+            self.logger.warning("Storage client unavailable, skipping bucket check")
+            return
+
+        get_bucket = getattr(storage, "get_bucket", None)
+        if not callable(get_bucket):
+            self.logger.warning("Storage get_bucket unavailable, skipping bucket check")
+            return
+
+        def _check_and_create() -> None:
+            try:
+                get_bucket(bucket_name)
+                self.logger.debug("Storage bucket already exists", bucket=bucket_name)
+            except Exception:  # noqa: BLE001
+                create_bucket = getattr(storage, "create_bucket", None)
+                if not callable(create_bucket):
+                    self.logger.warning(
+                        "Storage create_bucket unavailable, skipping bucket creation"
+                    )
+                    return
+                try:
+                    create_bucket(bucket_name, options={"public": False})
+                    self.logger.info("Storage bucket created", bucket=bucket_name)
+                except Exception as exc:  # noqa: BLE001
+                    msg = str(exc).lower()
+                    if "already exists" in msg or "duplicate" in msg:
+                        self.logger.debug(
+                            "Storage bucket already exists (race)", bucket=bucket_name
+                        )
+                        return
+                    self.logger.warning(
+                        "Failed to create storage bucket",
+                        bucket=bucket_name,
+                        error=str(exc),
+                    )
+
+        await asyncio.to_thread(_check_and_create)
+
 
 supabase_service: SupabaseService = register_service_instance(
     "supabase", SupabaseService()