feat(engine): 添加MCP连接管理和工具集成功能

- 集成MCP连接管理器，支持MCP服务器连接
- 添加多种内置工具：ClarifyTool、CronTool、DelegateTool、ExecuteCodeTool、
  PatchFileTool、ProcessTool、SendMessageTool、SpawnTool、TerminalTool、
  TodoTool、WebFetchTool、WebSearchTool、WriteFileTool等
- 实现工具注册和装配功能
- 添加技能选择上下文参数
- 支持思考模式控制参数thinking_enabled

feat(coordinator): 重构任务执行计划器参数命名

- 将learning_candidate_enabled重命名为allow_candidate_generation
- 更新TeamGraphScheduler中的参数传递
- 修改LocalAgentRunner中的相关参数处理
- 更新README文档中的相应描述

refactor(context): 标准化工具调用参数格式

- 添加_json导入用于参数序列化
- 实现_provider_tool_calls方法标准化OpenAI兼容的工具调用载荷
- 修复工具调用中参数非字符串类型的序列化问题

refactor(session): 优化消息历史记录过滤逻辑

- 修改get_messages_as_conversation为基于运行状态过滤消息
- 排除未完成、失败或错误结束的运行记录
- 改进对话历史的可见性控制机制

fix(store): 修复FTS索引重建逻辑

- 添加异常处理防止FTS索引创建失败
- 实现_rebuild_fts_index方法重新构建全文搜索索引
- 优化索引触发器和表的维护流程

app-instance/backend/beaver/foundation/config/schema.py

@@ -39,6 +39,65 @@ class EmbeddingConfig:
     request_timeout_seconds: float | None = None
 
 
+@dataclass(slots=True)
+class MCPServerConfig:
+    """One configured MCP server.
+
+    Transport is inferred from fields:
+    - command => local stdio MCP server
+    - url => remote streamable HTTP MCP server
+    """
+
+    command: str = ""
+    args: list[str] = field(default_factory=list)
+    env: dict[str, str] = field(default_factory=dict)
+    url: str = ""
+    headers: dict[str, str] = field(default_factory=dict)
+    auth_mode: str = "none"
+    auth_audience: str = ""
+    auth_scopes: list[str] = field(default_factory=list)
+    tool_timeout: int = 30
+    sensitive: bool = False
+    kind: str = "online"
+    category: str = "online"
+    managed: bool = False
+    display_name: str = ""
+    source: str = "config"
+
+    @property
+    def transport(self) -> str:
+        return "stdio" if _clean(self.command) else "http"
+
+
+@dataclass(slots=True)
+class ToolsConfig:
+    """Runtime tool configuration."""
+
+    restrict_to_workspace: bool = True
+    mcp_servers: dict[str, MCPServerConfig] = field(default_factory=dict)
+
+
+@dataclass(slots=True)
+class AuthzConfig:
+    """External AuthZ service configuration."""
+
+    enabled: bool = False
+    base_url: str = ""
+    request_timeout_seconds: int = 10
+    outlook_mcp_url: str = ""
+
+
+@dataclass(slots=True)
+class BackendIdentityConfig:
+    """This backend's AuthZ client identity."""
+
+    backend_id: str = ""
+    client_id: str = ""
+    client_secret: str = ""
+    name: str = ""
+    public_base_url: str = ""
+
+
 @dataclass(slots=True)
 class BeaverConfig:
     """Config loaded once per backend sandbox instance."""
@@ -46,6 +105,9 @@ class BeaverConfig:
     agents_defaults: AgentDefaultsConfig = field(default_factory=AgentDefaultsConfig)
     providers: dict[str, ProviderConfig] = field(default_factory=dict)
     embedding: EmbeddingConfig = field(default_factory=EmbeddingConfig)
+    tools: ToolsConfig = field(default_factory=ToolsConfig)
+    authz: AuthzConfig = field(default_factory=AuthzConfig)
+    backend_identity: BackendIdentityConfig = field(default_factory=BackendIdentityConfig)
     config_path: Path | None = None
 
     @property
@@ -69,7 +131,13 @@ class BeaverConfig:
         """
 
         resolved_model = _clean(model) or self.default_model
-        resolved_provider = _clean(provider_name) or self._infer_provider(resolved_model)
+        requested_provider = _clean(provider_name)
+        enabled_providers = self._enabled_provider_names()
+        resolved_provider = (
+            requested_provider
+            if requested_provider and requested_provider in enabled_providers
+            else self._infer_provider(resolved_model)
+        )
         provider_cfg = self.providers.get(resolved_provider or "") if resolved_provider else None
         payload: dict[str, Any] = {
             "model": resolved_model,
@@ -115,22 +183,36 @@ class BeaverConfig:
 
     def _infer_provider(self, model: str | None) -> str | None:
         configured_provider = _clean(self.agents_defaults.provider)
-        if configured_provider:
+        if configured_provider and configured_provider != "custom":
             return configured_provider
 
         if model and "/" in model:
             prefix = model.split("/", 1)[0]
-            if prefix in self.providers:
+            if prefix in self._enabled_provider_names():
                 return prefix
 
-        if len(self.providers) == 1:
-            return next(iter(self.providers))
+        enabled_providers = self._enabled_provider_names()
+        if len(enabled_providers) == 1:
+            return enabled_providers[0]
         return None
 
+    def _enabled_provider_names(self) -> list[str]:
+        return [
+            name
+            for name, provider in self.providers.items()
+            if name != "custom"
+            and any(
+                [
+                    _clean(provider.api_key),
+                    _clean(provider.api_base),
+                    provider.extra_headers,
+                ]
+            )
+        ]
+
 
 def _clean(value: str | None) -> str | None:
     if value is None:
         return None
     value = str(value).strip()
     return value or None
-