Add Dune-Origin header

[ivpusic]

Used for query execution attribution

[cursor]

PR Summary

Low Risk
Low risk: adds a static request header to all CLI API calls and bumps the API client dependency; behavior changes are limited to request metadata and dependency updates.

Overview
The CLI now sets env.Headers to include Dune-Origin: CLI for all API requests, enabling backend attribution of query executions.

Also bumps github.com/duneanalytics/duneapi-client-go from v0.4.4 to v0.4.5 (with corresponding go.sum updates).

^{Written by Cursor Bugbot for commit 4897fee. Configure here.}