I've split #2406 out of this one

I think it's a nice looking improvement in terms of comments. The templates get a tiny bit more complex, but I think that's ok.

@greptileai please review this draft.

Greptile Summary

This PR improves generated Godoc for client and server code. It changes:

• Adds operation-aware comments for generated client methods.
• Adds response wrapper details to ClientWithResponses method docs.
• Prefixes server handler summaries with the generated method name.
• Updates generated examples and test fixtures to match the new comments.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

_{Reviews (2): Last reviewed commit: "DROP-make-generate" | Re-trigger Greptile}

@greptileai review