feat: backporting existing raylib-cs examples and new official raylib examples to WASM, adopting raylib's original code style

Examples/Web/README.md

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+# Examples/Web — raylib-cs in the browser (WebAssembly)
+
+Runs the raylib examples in the browser via WebAssembly, with a dropdown to switch between them.
+It proves the `Raylib-cs` NuGet package's `browser-wasm` support end-to-end: the package's
+`buildTransitive` targets link the shipped `raylib.a` into the .NET wasm runtime.
+
+The browser-wasm configuration only activates when publishing with
+`RuntimeIdentifier=browser-wasm`; normal solution builds don't need the `wasm-tools` workload.
+
+## Prerequisites
+
+- .NET 10 SDK
+- `dotnet workload install wasm-tools`
+- The `Raylib-cs` package matching `$(RaylibCsVersion)` (see `Directory.Build.props`) — from
+  nuget.org, or built locally into the repo's `./nuget` feed (`dotnet pack Raylib-cs -c Release --output nuget`).
+
+## Build
+
+```bash
+dotnet publish Examples -f net10.0 -r browser-wasm -c Release
+# -> Examples/bin/Release/net10.0/browser-wasm/AppBundle/
+```
+
+### Toolchain caveat
+
+If the link step fails with `wasm-opt: Unknown option '--enable-bulk-memory-opt'`, the installed
+`wasm-tools` workload is out of sync with the SDK (stale workload band or a system EMSDK on
+PATH); fix with `dotnet workload update`. As a safety net, `Examples.csproj` defaults
+browser-wasm publishes to unoptimized native linking; an optimized publish can override those
+properties.
+
+## Run
+
+WebAssembly must be served over HTTP (not `file://`):
+
+```bash
+dotnet serve -d Examples/bin/Release/net10.0/browser-wasm/AppBundle    # dotnet tool install -g dotnet-serve
+# or:  npx http-server Examples/bin/Release/net10.0/browser-wasm/AppBundle
+```
+
+Open the printed URL and use the **Example** dropdown to switch examples.
+
+## Canvas scaling modes
+
+The render buffer stays fixed at `800x450`; display scaling is CSS-only. Pick with the **Scale**
+dropdown (or `?scale=` query param):
+
+- `native` (default): exact `800x450` CSS pixels.
+- `integer`: largest whole-number multiple that fits, centered with letterboxing (pixel-perfect).
+- `fit`: fills the viewport preserving aspect ratio (can be fractional, less crisp).
+
+Scaling is computed in device pixels and converted back to CSS via `devicePixelRatio`, so the
+modes behave consistently across OS scale and browser zoom. The status bar shows the live numbers
+(`DPR`, CSS size, backing size, scale): `integer` should stay crisp at any OS scale or zoom, and
+`native` should always report `Scale 1.00`.
+
+## How it works
+
+A browser can't run raylib's blocking `while (!WindowShouldClose())` loop (it would freeze the
+page), so frames are driven from JavaScript:
+
+- `Host.Main()` calls `InitWindow` once; `main.js` then populates the dropdown and selects the
+  first example via `Host.SetExample`, so init failures surface in the on-page error banner.
+- `main.js` binds the page `<canvas>` to the runtime and calls `Host.UpdateFrame()` from a
+  `requestAnimationFrame` loop paced to the current example's `TargetFps` (raylib's own limiter
+  busy-waits and would peg the main thread). The `Host` methods it calls are `[JSExport]`.
+- On switch, `Host.SetExample` unloads the previous example, resets the cursor to visible, and
+  applies the next `TargetFps`. Cursor hiding and `ConfigFlags` are not honored in the browser.
+  If `Init` or `Update` throws, the example is unloaded and an error banner is shown.
+- Each example is a single `.cs` file implementing `IExample` (`Init` / `Update` / `Unload`); the
+  host owns the window, so examples never call `InitWindow`/`CloseWindow`. Platform differences
+  (e.g. GLSL 100 vs 330) are handled inline with `#if BROWSER` guards, not separate files.
+
+## Adding more examples
+
+Examples are **auto-discovered by reflection** (`ExampleRegistry.DiscoverAll`) — no list to edit.
+Drop a new `.cs` file in the matching category folder implementing `IExample`, splitting the
+original monolithic `Main` as:
+
+```
+Main() { <setup>; while(!WindowShouldClose()){ <body> } <cleanup> }
+  ->  Init()  { <setup, minus InitWindow/SetTargetFPS> }   // loop-spanning locals become fields
+      Update(){ <body> }                                   // keep BeginDrawing..EndDrawing
+      Unload(){ <cleanup, minus CloseWindow> }
+```
+
+Keep the standalone `static Main()` as a thin driver so the example still runs on its own.
+
+If an example can't run on single-threaded wasm, add its type to `DesktopExcludedFromBrowser` in
+`ExampleRegistry.cs`; `BrowserOnly` is the inverse list. Assets under `resources/` are bundled
+into the wasm virtual filesystem automatically.