daemon: fix 100% CPU spin on long-running kernel executions

src/nbexec/daemon/server.py

@@ -134,6 +134,10 @@ async def _exec_with_disconnect(self, session, code, reader):
 
         if exec_future in done:
             disconnect.cancel()
+            try:
+                await disconnect
+            except asyncio.CancelledError:
+                pass
             return exec_future.result()
 
         # reader.read returned — check if it's truly EOF

src/nbexec/session/manager.py

@@ -64,7 +64,7 @@ def execute(self, code: str) -> dict:
         self._execution_count += 1
 
         try:
-            reply = self.kernel.execute(code)
+            reply = self.kernel.execute(code, timeout=None)
         except Exception as e:
             error_output = {
                 "output_type": "error",