Have you considered adding LSP support? I anticipate go-to-defintion/implementation and go-to-usages being pretty useful via MCP or function calling. I started doing this for an internal tool a while back (to help with understanding some really poorly written Ruby) but I don't find any joy in coding this kind of stuff and have been hoping for someone else to do it instead.
Yeah, I've definitely thought about this. I would likely try to do it through tree-sitter to keep it as light and language-agnostic as possible vs. language-specific LSP integrations, but I agree it could be very helpful.