Introduce Initialization options that are passed to ServerSession

[dsp-ant]

Depends on:

• Type Fixes #15

There is currently no way for server implementations to pass capabilities, server name and server version to the protocol. We now introduce an InitializationOption object that can be passed. Users of this are free to use the new get_capabilities to fill capabilities based on the defined handlers. This will allow patterns such as

app = Server()

@app.list_prompts()
async def list_my_prompts(...):
   ...

app.run(..., InitializationOptions(..., capabilities=app.get_capabilities()))

This is mostly an RFC. I am not sold on the specific approach but want to get something going so that we can correctly negotiate capabilities between our Zed implementation of the protocol and Python servers.

[jspahrsummers]

Can we use a Pydantic model here for consistency?

[jspahrsummers]

Can we infer this by default, instead of always requiring it to be passed in?

[dsp-ant]

I rather be explicit about it for now. I'll keep it in mind however.

[jspahrsummers]

Can we add a test for this?

[jspahrsummers]

It seems like this code would be simpler if this is just passed in directly to the ServerCapabilities constructor. I guess the point is to do the None filtering, though—I wish we could figure out how to get Pydantic to do that

[dsp-ant]

Okay I talked with Claude about this. There might be ways do this with pydantic, but we both prefer the more explicit approach. I added a helper function so people can pass it via app.create_initialization_option(). If you feel strongly about it, i am happy to change it.