feat(agent): add interrupt-aware tool dispatcher

backend/src/v1/agent/tool_dispatcher.py

@@ -0,0 +1,54 @@
+from __future__ import annotations
+
+from typing import Any
+
+from pydantic import BaseModel
+
+
+class InterruptResult(BaseModel):
+    interrupt_type: str
+    tool_name: str
+    tool_args: dict[str, Any]
+
+
+class BackendExecutionResult(BaseModel):
+    tool_name: str
+    tool_args: dict[str, Any]
+    result: Any | None = None
+
+
+class ToolDispatcher:
+    def dispatch(
+        self, tool: dict[str, Any]
+    ) -> InterruptResult | BackendExecutionResult:
+        return dispatch_tool_call(tool)
+
+
+def dispatch_tool_call(
+    tool: dict[str, Any],
+) -> InterruptResult | BackendExecutionResult:
+    name = tool["name"]
+    target = tool["execution_target"]
+    args = tool.get("args", {})
+
+    if target == "frontend":
+        return InterruptResult(
+            interrupt_type="tool_execution",
+            tool_name=name,
+            tool_args=args,
+        )
+
+    if target == "backend":
+        requires_approval = tool.get("requires_approval", False)
+        if requires_approval:
+            return InterruptResult(
+                interrupt_type="approval_required",
+                tool_name=name,
+                tool_args=args,
+            )
+        return BackendExecutionResult(
+            tool_name=name,
+            tool_args=args,
+        )
+
+    raise ValueError(f"Unknown execution_target: {target}")