chore: extract connect to an API plugin

[pujitm]

Summary by CodeRabbit

• New Features

  • Introduced a unified, JSON-schema-based settings system for API configuration and plugin settings, accessible via new GraphQL queries and mutations.
  • Added modular NestJS plugin architecture for Unraid Connect, including new modules for cloud, remote access, and system/network management.
  • Added granular connection and remote access state tracking, with new GraphQL types and resolvers for cloud and connection status.
  • Implemented event-driven and service-based management for SSO users, API keys, and dynamic remote access.
  • Enhanced UI components and queries to support unified settings and restart detection.

• Improvements

  • Refactored configuration and state management to use service-based patterns, replacing direct store access and Redux logic.
  • Migrated legacy config files to new JSON formats with validation and persistence helpers.
  • Centralized global dependencies and shared services for plugins and CLI modules.
  • Improved logging, error handling, and lifecycle management for connections and background jobs.
  • Updated and expanded documentation for plugin development and settings management.

• Bug Fixes

  • Improved handling of missing config files and ensured safe persistence.
  • Enhanced error reporting and validation in remote access and connection services.

• Removals

  • Removed deprecated Redux slices, listeners, and legacy cloud/remote access logic.
  • Deleted obsolete test files, scripts, and unused code related to the old state/store approach.

• Tests

  • Added new unit tests for settings merging, URL resolution, and cloud connectivity checks.

• Style

  • Applied consistent formatting, import reorganization, and code style improvements across modules.

• Chores

  • Updated build scripts, Dockerfiles, and development environment setup to support new dependencies and workflows.
  • Expanded .gitignore and configuration files for improved build artifact management.