Copilot CLI activity now included in usage metrics totals and feature breakdowns

GitHub Copilot's CLI activity is now integrated into the top-level usage metrics totals and dimensional breakdowns in the Copilot usage metrics API. Previously, CLI metrics were reported separately in a standalone `totals_by_cli` section, leaving top-level totals reflecting IDE activity only. Now fields like `code_generation_activity_count`, `code_acceptance_activity_count`, and `loc_added_sum` combine IDE and CLI data. CLI also appears as `feature=copilot_cli` in feature, model, and language breakdowns. Admins should note that top-level totals have changed meaning and may see higher numbers if their dashboards assumed IDE-only values.