Enhancement: Replace Concurrent::AtomicFixnum with pure Ruby AtomicCounter

• Removes external dependency on concurrent-ruby for atomic fixnum operations
• Introduces Shoryuken::Helpers::AtomicCounter as a thread-safe alternative using Mutex
• Reduces gem footprint while maintaining full functionality

Enhancement: Replace Concurrent::AtomicBoolean with pure Ruby AtomicBoolean

• Removes external dependency on concurrent-ruby for atomic boolean operations
• Introduces Shoryuken::Helpers::AtomicBoolean extending AtomicCounter
• Further reduces gem footprint while maintaining full functionality

Enhancement: Replace Concurrent::Hash with pure Ruby AtomicHash

• Removes external dependency on concurrent-ruby for hash operations
• Introduces Shoryuken::Helpers::AtomicHash with mutex-protected writes and concurrent reads
• Ensures JRuby compatibility while maintaining high performance for read-heavy workloads
• #866
• #867
• #868

Enhancement: Replace core class extensions with helper utilities

• Removes all core Ruby class monkey-patching (Hash and String extensions)
• Introduces Shoryuken::Helpers::HashUtils.deep_symbolize_keys for configuration processing
• Introduces Shoryuken::Helpers::StringUtils.constantize for dynamic class loading
• Eliminates unnecessary ActiveSupport dependencies
• Completely removes lib/shoryuken/core_ext.rb file
• Maintains all existing functionality while following Ruby best practices
• Improves code maintainability and reduces global namespace pollution

Enhancement: Implement Zeitwerk autoloading

• Replaces manual require statements with Zeitwerk-based autoloading
• Adds zeitwerk dependency for modern Ruby module loading
• Splits polling classes into properly named files (BaseStrategy, QueueConfiguration)
• Reduces startup overhead and improves code organization
• Maintains backward compatibility while modernizing the codebase

Enhancement: Increase SendMessageBatch to 1MB to align with AWS

• #864

Enhancement: Replace OpenStruct usage with Struct for inline execution

• #860

Enhancement: Configure server side logging (BenMorganMY)

• #844

Enhancement: Use -1 as thread priority

• #825

Enhancement: Add Support for message_attributes to InlineExecutor

• #835

Enhancement: Introduce trusted publishing

• #840

Enhancement: Add enqueue_after_transaction_commit? for Rails 7.2 compatibility

• #777

Enhancement: Bring Ruby 3.4 into the CI

• #805

Fix integration tests by updating aws-sdk-sqs and replacing moto with LocalStack

• #782
• #783

Breaking: Remove support of Ruby versions older than 3.1

• #783
• #850

Breaking: Remove support of Rails versions older than 7.0

• #783
• #850

Breaking: Require aws-sdk-sqs >= 1.66:

• #783