Accept raced `TransportClosed` diagnostics

The `@context` debugger E2E intentionally closes its channel.
Teardown can surface from either local error shipment or the peer
receive task.
The RPC response fix makes local close win under CI, while the test
required both scheduler-dependent diagnostics.

Keep the common debugger and cancellation assertions, then accept
either transport-close report. This preserves real actor-tree
teardown coverage without depending on task scheduling order.

Review: PR #480 (goodboy)
https://github.com/goodboy/tractor/pull/480

(this patch was generated in some part by `opencode` using
`gpt-5.6-sol` (`openai`))

tests/devx/test_debugger.py

@@ -1307,19 +1307,31 @@ def test_ctxep_pauses_n_maybe_ipc_breaks(
             if _non_linux:
                 tpt: str = 'TCP'
 
-            assert_before(
+            before: str = assert_before(
                 child,
                 ['peer IPC channel closed abruptly?',
                  'another task closed this fd',
                  'Debug lock request was CANCELLED?',
-                 f"'Msgpack{tpt}Stream' was already closed locally?",
-                 f"TransportClosed: 'Msgpack{tpt}Stream' was already closed 'by peer'?",
                  ]
 
                  # XXX races on whether these show/hit?
                   # 'Failed to REPl via `_pause()` You called `tractor.pause()` from an already cancelled scope!',
                   # 'AssertionError',
             )
+
+            # Error shipment and peer receive race after local close.
+            # Either diagnostic proves the transport was torn down.
+            closed_locally: str = (
+                f"'Msgpack{tpt}Stream' was already closed locally?"
+            )
+            closed_by_peer: str = (
+                f"TransportClosed: 'Msgpack{tpt}Stream' was "
+                f"already closed 'by peer'?"
+            )
+            assert (
+                closed_locally in before
+                or closed_by_peer in before
+            )
             # OSc(ancel) the hanging tree
             do_ctlc(
                 child=child,