Create ConfigurableTrayService base class for reusable tray service logic

[Olbrasoft]

Problem

Currently, each project (PushToTalk, VirtualAssistant) needs to create its own wrapper service around TrayIconManager:

• PushToTalkTrayService - handles main icon, animated icon, menu events
• VirtualAssistantTrayService - handles single icon with mute state, different menu

While each project has unique requirements (different events, state, menu structure), there's common boilerplate code for:

• Icon creation and rendering
• Basic lifecycle management
• Common patterns for menu building

Proposed Solution

Create an abstract ConfigurableTrayService base class in the NuGet package that provides:

public abstract class ConfigurableTrayService : IDisposable
{
    protected readonly TrayIconManager _manager;
    protected readonly ILogger _logger;
    protected ITrayIcon? _mainIcon;
    
    protected ConfigurableTrayService(ILogger logger, TrayIconManager manager)
    {
        _logger = logger;
        _manager = manager;
    }
    
    // Shared logic
    protected void CreateIcon(string iconPath, string tooltip, string id)
    {
        // Common icon creation logic
    }
    
    // Project-specific overrides
    protected abstract void BuildMenu(ITrayIcon icon);
    protected abstract void OnIconClicked();
    
    public abstract void Dispose();
}

Then projects only need to implement their specific logic:

public class PushToTalkTrayService : ConfigurableTrayService
{
    public event Action? OnQuitRequested;
    
    protected override void BuildMenu(ITrayIcon icon)
    {
        // PushToTalk-specific menu items
    }
    
    protected override void OnIconClicked()
    {
        // PushToTalk-specific click behavior
    }
}

Benefits

• Less boilerplate: Common icon creation/rendering logic in base class
• Flexibility: Each project can still customize events, state, menu structure
• Maintainability: Bug fixes in common logic benefit all projects
• Testability: Base class logic can be tested once

Alternatives Considered

Fully generic wrapper with configuration: Too complex - would need dozens of parameters/callbacks for different events, menu structures, state management. Current approach (base class with abstract methods) provides better balance.

Implementation Tasks

• Design base class API
• Implement ConfigurableTrayService in SystemTray.Linux
• Migrate PushToTalkTrayService to inherit from base class
• Migrate VirtualAssistantTrayService to inherit from base class
• Update documentation with usage examples
• Publish new NuGet version (1.1.0?)