Current topic: "Processing PR #108 (Billing Client)"
Topic summary: I have merged PR #107. Now I am starting on PR #108, which bumps the Billing Client from 8.3.0 to 9.0.0. Since this is a major version update, I will carefully review any compilation errors or test failures. I'll follow the same procedure: checkout, run JVM tests, and then run GPU-accelerated smoke tests.

Strategic Intent: Processing PR #108 (Billing Client) and checking for breaking changes.