refactor(node): dispatch MNP messages through a table

The pre-authentication guards stay explicit code, in the same order and
text. After the handshake, a table maps each type to its handler and to
whether it runs as a task, the choice each branch made; the three inline
blocks become StreamingMixin methods, unchanged. The dispatch golden is
identical, including types that are not strings.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/packages/meshbay-node/tests/test_task_lifetime.py b/packages/meshbay-node/tests/test_task_lifetime.py
index a8445fa..6f0abb7 100644
--- a/packages/meshbay-node/tests/test_task_lifetime.py
+++ b/packages/meshbay-node/tests/test_task_lifetime.py
@@ -249,7 +249,10 @@ def test_chunks_wait_for_room_on_the_channel(session):
 
 def test_answering_a_chunk_does_not_block_the_message_loop(session):
     """It waits for buffer room, and the acks that free it arrive on this loop."""
-    assert "self._spawn(self._do_file_request(msg))" in session, (
+    from meshbay_common.protocol import MNP
+    from meshbay_node.transport.webrtc.dispatch import _HANDLERS, SPAWNED
+
+    assert _HANDLERS[MNP.FILE_REQUEST] == ("_do_file_request", SPAWNED), (
         "answering inline would stall the uploads whose acks drain the buffer")