Changes made for Pathfinder V5 PC's.

Pathfinder now automatically detects new or removed machine configurations at startup. If a new configuration is added to the machine (through an update or manually), it will appear in the "Change Machine Configuration" list the next time Pathfinder starts. If a configuration file is removed, it will be cleaned up from the list automatically. No need to delete ConfigurationSettings.json to pick up changes anymore.

ConfigurationSettings.cs — Added SyncAvailableConfigurations() method that compares configs on disk against ConfigurationSettings.json at startup, adds new ones, removes stale ones, sorts the list alphabetically, and clears SelectedConfig if its files were removed.

ApplicationManager.cs — Added call to SyncAvailableConfigurations() in Start() after corruption check, before any configuration selection logic.