Release

Overview

This release completes the implementation of Step-Level Concurrency Control for PartitionStep, formalizes Partition Execution Semantics, expands automated Failure Matrix integration tests, and introduces OpenTelemetry observability across worker executions.

concurrency Parameter Support: Added partition.concurrency configuration in JSL step definitions, allowing developers to set maximum concurrent partition worker bounds per step.
Safe Defaults: Defaults to concurrency: 1 (enforcing "Serial-First" execution safety) when unspecified.
Semaphore Throttling: Integrated golang.org/x/sync/semaphore inside PartitionStep.Execute to throttle active workers and prevent resource exhaustion (e.g., DB connection starvation, memory spikes).

Worker Lifecycle State Machine: Formalized partition worker state transitions (STARTING $\rightarrow$ STARTED $\rightarrow$ COMPLETED / FAILED / STOPPED).
Cancellation Propagation: Standardized context cancellation and errgroup error teardown rules between Controller Step and active Partition Workers.

Failure Matrix Coverage (partition_step_test.go): Added extensive integration test cases covering edge-case scenarios:
- Partial worker failure state aggregation
- Context cancellation propagation
- Multi-worker failure aggregation
- Worker execution timeouts
- Job repository persistence failure handling
OpenTelemetry Instrumentation: Added worker-level OpenTelemetry span tracking for worker start, success, and error events with safe NoOp fallbacks when unconfigured.

JSL Configuration: When defining type: partition steps in JSL, configure concurrency based on target workload requirements (e.g., concurrency: 8). Unconfigured steps default to 1.
Observability: Partition worker traces will now automatically export through configured OpenTelemetry collectors.