Rolling deployments for zero-downtime model updates

Introduced rolling deployments for zero-downtime model updates. Implemented two provisioning modes: `max_surge` (temporarily exceeds steady-state capacity) and `max_unavailable` (stays within original resource footprint). Developed a durable workflow orchestration for stateful deployments, including automatic retries and pause/resume semantics. Integrated autoscaling coordination to manage load spikes during rollouts. Added mid-deploy controls (pause, resume, cancel, force cancel, force roll forward) and a configurable stabilization period.