Issue listing and running tools from a server in 0.8.0

[alexhancock]

Describe the bug
Finding issues with the SSE connection the inspector makes in 0.8.0 - seemingly some issue when multiple runs of the inspector occur after one another.

To Reproduce
Follow instructions in https://github.com/alexhancock/snippets/tree/main/inspector-sse-connection-failed-example

Observe errors in the UI
Error POSTing to endpoint (HTTP 500): SSE connection not established

Expected behavior
Tools should be able to be listed and run

[alexhancock]

Thanks @cliffhall @olaservo @max-stytch !