Revert "fix(runtime): make plugin and box connectors resilient"

This reverts commit 0b461e5830.

src/langbot/pkg/utils/managed_runtime.py

@@ -3,7 +3,6 @@
 from __future__ import annotations
 
 import asyncio
-import contextlib
 import os
 import sys
 from typing import TYPE_CHECKING, Awaitable, Callable
@@ -28,8 +27,6 @@ class ManagedRuntimeConnector:
         self.ap = ap
         self.runtime_subprocess = None
         self.runtime_subprocess_task = None
-        self._lifecycle_lock = asyncio.Lock()
-        self._closing = False
 
     async def _start_runtime_subprocess(self, *args: str) -> None:
         """Launch a local runtime as a subprocess of the current Python interpreter.
@@ -89,23 +86,3 @@ class ManagedRuntimeConnector:
         if self.runtime_subprocess_task is not None:
             self.runtime_subprocess_task.cancel()
             self.runtime_subprocess_task = None
-
-    async def _close_managed_subprocess(self) -> None:
-        """Terminate, escalate, and reap the optional owned subprocess."""
-        process = self.runtime_subprocess
-        wait_task = self.runtime_subprocess_task
-        if process is not None and process.returncode is None:
-            with contextlib.suppress(ProcessLookupError):
-                process.terminate()
-            try:
-                await asyncio.wait_for(process.wait(), timeout=3)
-            except asyncio.TimeoutError:
-                with contextlib.suppress(ProcessLookupError):
-                    process.kill()
-                await process.wait()
-        if wait_task is not None and wait_task is not asyncio.current_task():
-            if not wait_task.done():
-                wait_task.cancel()
-            await asyncio.gather(wait_task, return_exceptions=True)
-        self.runtime_subprocess = None
-        self.runtime_subprocess_task = None