Agentic AI, enterprise control: Self-hosted Duo Agent Platform and BYOM

Introduces self-hosted GitLab Duo Agent Platform for online cloud licenses with usage-based billing via GitLab Credits, enabling data residency and control by allowing users to run models on their own infrastructure. Also introduces 'Bring Your Own Model' (BYOM) functionality, allowing connection of third-party or self-hosted models via the GitLab AI Gateway for granular mapping and governance.