Python: Add Python agent runtime project infrastructure (#563)

* Add Python agent runtime project infrastructure.

* lint.

* Rename agent_runtime dir to agent_framework_runtime.

* fix uv.lock

* Update pyproject for rename.

* Update python/packages/runtime/agent_framework_runtime/agent_actor.py

Co-authored-by: Eric Zhu <ekzhu@users.noreply.github.com>

* Add runtime package to workspace and optional dependencies.

---------

Co-authored-by: Eric Zhu <ekzhu@users.noreply.github.com>

python/packages/runtime/agent_framework_runtime/__init__.py

@@ -0,0 +1,10 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+# Agent Runtime - Python Implementation
+
+from .agent_actor import ActorId, RequestStatus
+
+__all__ = [
+    "ActorId",
+    "RequestStatus",
+]

python/packages/runtime/agent_framework_runtime/agent_actor.py

@@ -0,0 +1,26 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Core actor abstractions for the Python actor runtime."""
+
+from dataclasses import dataclass
+from enum import Enum
+
+
+@dataclass(frozen=True, kw_only=True)
+class ActorId:
+    """Unique identifier for an actor instance."""
+
+    type_name: str
+    instance_id: str
+
+    def __str__(self) -> str:
+        """Return the string representation of the actor ID."""
+        return f"{self.type_name}/{self.instance_id}"
+
+
+class RequestStatus(Enum):
+    """Status of a request being processed by an actor."""
+
+    PENDING = "pending"
+    COMPLETED = "completed"
+    FAILED = "failed"