Add optional source col for memories

[murrayju]

This adds a source column to memory, making it possible to trace back memories to their origins.

The expectation is that Eon will (deterministically) set the URL of the slack message containing the bot mention, where the memory was created.

[MasterOdin]

We'll probably need to explicitly tell eon to fill this field in along with the structure of the slack urls to expect.

Something like https://ai.pydantic.dev/toolsets/#preparing-tool-definitions this might be useful to just plug that info into the tool description directly, vs plugging it into the prompt?

[murrayju]

We'll probably need to explicitly tell eon to fill this field in along with the structure of the slack urls to expect.

Something like https://ai.pydantic.dev/toolsets/#preparing-tool-definitions this might be useful to just plug that info into the tool description directly, vs plugging it into the prompt?

I was actually thinking that we'd want to override the parameter in the agent code, vs allowing the llm to specify it.