[TSP] Parameter hints don't work with TSP

[rchiodo]

1. Enable Pyrefly as a TSP server
2. Add print("foo", sep=) to a python file
3. Trigger parameter hints on the sep=

Expected result:
Parameter hints appear and sep is bolded.

Actual result:
Nothing happens

[gramster]

I see this in the output:

2026-05-05 16:41:16.555 [error] Notifying file events failed.
Message: Client is not running
Code: -32096