SAO Phase 3a — Driver Framework Foundation

Build the load-bearing integration abstraction for SAO — the driver base contract, the per-capability contracts domain services depend on, an open driver registry, the Connection model, environment-resolved credentials, and a reusable per-capability conformance suite — with no network access and no concrete external driver. The deliverable proves the abstraction end-to-end offline via one in-memory reference driver that passes conformance. Concrete drivers (Redmine, GitHub, …) and ticket synchronization are explicitly out of scope; they land in Phase 3b once this foundation and Phase 2 exist.