Woops, need to use `.push_async_callback()`

For non-full-`.__aexit__()` handlers need this method instead (facepalm).
Also create and assign the `AnnotCtl._annot_stack: AsyncExitStack` just
before yielding the client since it's not needed prior and ensures annot
removal happens **before** ipc teardown.

piker/ui/_remote_ctl.py

@@ -24,6 +24,7 @@ from contextlib import (
     asynccontextmanager as acm,
     AsyncExitStack,
 )
+from functools import partial
 from pprint import pformat
 from typing import (
     # Any,
@@ -164,7 +165,10 @@ class AnnotCtl(Struct):
     '''
     ctx2fqmes: dict[str, str]
     fqme2ipc: dict[str, MsgStream]
-    _annot_stack = AsyncExitStack()
+    _annot_stack: AsyncExitStack
+
+    # runtime-populated mapping of all annotation
+    # ids to their equivalent IPC msg-streams.
     _ipcs: dict[int, MsgStream] = {}
 
     async def add_rect(
@@ -209,8 +213,11 @@ class AnnotCtl(Struct):
         aid: int = await ipc.receive()
         self._ipcs[aid] = ipc
         if not from_acm:
-            self._annot_stack.push_async_exit(
-                self.remove(aid)
+            self._annot_stack.push_async_callback(
+                partial(
+                    self.remove,
+                    aid,
+                )
             )
         return aid
 
@@ -294,15 +301,7 @@ async def open_annot_ctl(
         ctx2fqmes: dict[str, set[str]] = {}
         fqme2ipc: dict[str, MsgStream] = {}
         stream_ctxs: list[AsyncContextManager] = []
-        client = AnnotCtl(
-            ctx2fqmes=ctx2fqmes,
-            fqme2ipc=fqme2ipc,
-            # _annot_stack=annots_stack,
-        )
-
         async with (
-            # AsyncExitStack() as annots_stack,
-            client._annot_stack,  # as astack,
             trionics.gather_contexts(ctx_mngrs) as ctxs,
         ):
             for (ctx, fqmes) in ctxs:
@@ -330,6 +329,13 @@ async def open_annot_ctl(
                     for fqme in fqmes:
                         fqme2ipc[fqme] = stream
 
+                # NOTE: on graceful teardown we always attempt to
+                # remove all annots that were created by the
+                # entering client.
+                async with AsyncExitStack() as annots_stack:
+                    client = AnnotCtl(
+                        ctx2fqmes=ctx2fqmes,
+                        fqme2ipc=fqme2ipc,
+                        _annot_stack=annots_stack,
+                    )
                     yield client
-                # TODO: on graceful teardown should we try to
-                # remove all annots that were created/modded?