Component base classes and shared infrastructure.

// Inside a component's .razor file:
<div @attributes="RootAttributes"
     class="@GetMergedClass("my-component-base-css")">
    @ChildContent
</div>

// The RootAttributes property merges everything:
// 1. AdditionalAttributes applied first (lowest priority)
// 2. Id, Class, Style override (highest priority)
// 3. data-sillium-component and data-sillium-id auto-added

// Consumer usage — all extra attributes flow through:
<Button Color="Color.Success"
        Class="mt-4"
        Style="min-width: 200px;"
        data-testid="save-btn"
        aria-label="Save changes"
        Text="Save" />

// GetMergedClass concatenates component CSS with user's Class parameter.
// Signature: protected string GetMergedClass(string baseClasses)

// Inside a component:
<div class="@GetMergedClass("btn btn--primary btn--md")">
    @ChildContent
</div>

// If user passes Class="mt-4 shadow-lg", the result is:
// class="btn btn--primary btn--md mt-4 shadow-lg"

// If Class is null, only baseClasses are returned:
// class="btn btn--primary btn--md"

// Auto-registration happens in SilliumComponentBase:
protected override void OnInitialized()
{
    base.OnInitialized();
    _registry = ServiceProvider.GetService<DesignDevToolRegistry>();
    _registry?.Register(_instanceId, this);
}

public virtual void Dispose()
{
    _registry?.Unregister(_instanceId);
}

// DesignDevToolRegistry uses WeakReference<SilliumComponentBase>
// to avoid preventing garbage collection of disposed components.

// Live parameter overrides from the DevTool panel:
internal void SetDevOverride(string paramName, object? value)
{
    _devOverrides[paramName] = value;
    ApplyDevOverrides();
    InvokeAsync(StateHasChanged);
}

internal void ClearDevOverrides()
{
    _devOverrides.Clear();
    InvokeAsync(StateHasChanged);
}