How does Blazor's render mode system (Static, Interactive Server, Interactive WebAssembly, Interactive Auto) work in .NET 8+'s unified Blazor model?

Since .NET 8, a single Blazor project can mix render modes per component: Static Server-Side Rendering (no interactivity, fastest initial load), Interactive Server (SignalR-based, like classic Blazor Server), Interactive WebAssembly (client-side execution, like classic Blazor WASM), and Interactive Auto (starts with Server for instant interactivity, then switches to WebAssembly once the client-side runtime finishes downloading in the background) -- letting you choose the optimal trade-off per-component rather than committing the entire app to one model.

@page "/counter"
@rendermode InteractiveAuto

<button @onclick="IncrementCount">Count: @count</button>

@code {
    private int count = 0;
    private void IncrementCount() => count++;
}