feat：将timing分离成单独的subagent

src/maisaka/builtin_tool/continue_tool.py

@@ -0,0 +1,37 @@
+"""continue 内置工具。"""
+
+from typing import Optional
+
+from src.core.tooling import ToolExecutionContext, ToolExecutionResult, ToolInvocation, ToolSpec
+
+from .context import BuiltinToolRuntimeContext
+
+
+def get_tool_spec() -> ToolSpec:
+    """获取 continue 工具声明。"""
+
+    return ToolSpec(
+        name="continue",
+        brief_description="允许当前会话继续进入下一轮思考和工具执行。",
+        provider_name="maisaka_builtin",
+        provider_type="builtin",
+    )
+
+
+async def handle_tool(
+    tool_ctx: BuiltinToolRuntimeContext,
+    invocation: ToolInvocation,
+    context: Optional[ToolExecutionContext] = None,
+) -> ToolExecutionResult:
+    """执行 continue 内置工具。"""
+
+    del tool_ctx, context
+    return ToolExecutionResult(
+        tool_name=invocation.tool_name,
+        success=True,
+        content="当前对话继续进入下一轮思考和工具执行。",
+        metadata={
+            "pause_execution": True,
+            "timing_action": "continue",
+        },
+    )