Replaced the bot's audio handling system by removing Lavaplayer dependencies and migrating to a Lavalink v4 node. Updated `MusicManager`, `TrackScheduler`, and related classes to utilize the `LavalinkClient`. Refactored playlist and track loading logic, task integrations, and event dispatch to integrate with the remote node. Deprecated the custom Udio source, preserving references for a future plugin port. Documented configuration and deployment details for the new audio architecture.
Replaced the existing HttpServer implementation and associated handler classes (`AbstractHandler`, `ActionHandler`, `GuildHandler`, `RootHandler`) with a Javalin-based routing system. Improved modularity by introducing `ActionRoutes` and `GuildRoutes` for route definitions, and centralized JSON mapping using `GsonJsonMapper`. Simplified caching via the new `ResponseCache` utility, updated `WebModule` for cleaner timeout handling, and extended test coverage for API endpoints.
Redesigned task lifecycle management to properly cascade parent-child removals and synchronize database persistence on task deletion. Refactored task management to address memory leaks, concurrency collisions, and pending-task cleanup issues. Enhanced lookup performance, logging accuracy, and test coverage with a comprehensive unit test suite validating all task scenarios.
Decomposed the monolithic `dispatch()` method into modular components using `CommandPrecondition`, `ResultHandler`, and `UsageValidator`. Replaced inline checks and tightly-coupled logic with composable, testable classes, eliminating `instanceof` dependencies. Preserved existing behavior and improved maintainability for future feature additions.
Replaced unbounded thread pools in `ThreadManager` with bounded `ThreadPoolExecutor` to prevent memory exhaustion under load. Refactored shutdown logic to handle exceptions per-executor, set threads to daemon mode in `BaseThreadFactory`, and aligned synchronization patterns across multiple classes (`TaskManagerImpl`, `ChannelMessagePurger`, and `MusicManager`). Addressed lock cleanup races, double unlock issues, and static collection thread-safety concerns.
Reworked `Settings` class to replace the static singleton pattern with constructor injection of `SettingsProvider`, improving testability and modularity. Updated all affected classes, tests, and configurations to align with the new architecture.
Refactored scheduled tasks and moved them to a dedicated `scheduled` package. Replaced the legacy `ScheduledTaskManager` and `ScheduledTask` definitions with a redesigned architecture to improve maintainability. Updated related classes and configurations to adopt the new structure.