Ruby reactor locks

[arturictus]

This pull request introduces support for distributed exclusive locks and semaphores to the RubyReactor framework, enabling safe concurrent execution and resource limiting for reactors. The changes include a new DSL for configuring locking and semaphore behavior, integration with Redis for lock/semaphore primitives, and Sidekiq worker enhancements to handle lock contention gracefully. Comprehensive integration and unit tests are provided to ensure correct behavior.

Locking and Semaphore DSL:

• Added Lockable DSL module (ruby_reactor/dsl/lockable.rb) allowing reactors to declare exclusive locks (with_lock) and semaphores (with_semaphore) with customizable keys, TTLs, and limits.
• Reactors now include Lockable for easy configuration (reactor.rb).

Lock and Semaphore Implementation:

• Implemented distributed lock (Lock) and semaphore (Semaphore) classes with acquisition/release logic, error handling, and re-entrancy support (lock.rb, semaphore.rb). [1] [2]
• Integrated Redis-based lock and semaphore primitives via the new RedisLocking module (storage/redis_locking.rb) and included it in the Redis adapter (storage/redis_adapter.rb). [1] [2]

Executor and Worker Integration:

• Updated Executor to acquire locks/semaphores before execution/resume, raising specific errors on contention, and Sidekiq worker to reschedule jobs when locks are busy instead of failing. [1] [2] [3] [4] [5] [6]

Testing and Examples:

• Added example reactors demonstrating locking and semaphore usage (spec/examples/locking_reactors.rb).
• Added integration tests for lock/semaphore behavior and contention handling (spec/ruby_reactor/integration/locking_spec.rb).
• Added Sidekiq worker unit tests for lock acquisition failures and job rescheduling (spec/ruby_reactor/sidekiq_workers/worker_spec.rb).