[Observability] Logging: amber engine control-plane lifecycle/error logs #5328

Part of #4070.

Goal

Add human-readable lifecycle/error logging across the amber engine control plane.

Problem

The engine control plane (controller, worker lifecycle, scheduling, recovery/replay, client, network setup) emitted little to no log output, making it hard to follow a workflow's execution or diagnose failures.

Scope

• INFO/DEBUG/WARN/ERROR logging at control-plane boundaries via the AmberLogging trait.
• No per-tuple/per-message logging on the data hot path.
• Non-functional; no behavior change.

Branch: chore/logging-amber-engine