Add Playwright test infrastructure for wxWidgets WASM port

- Add tests/ directory with Playwright e2e tests
- Add minimal wxWidgets WASM test application
- Add build script for test app (scripts/build-wasm-test.sh)
- Update wxWidgets submodule with WASM build fixes
- Update .gitignore for test artifacts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/wasm-app/minimal_test.html

@@ -0,0 +1,114 @@
+<!doctype html>
+<html lang="en-us">
+  <head>
+    <meta charset="utf-8">
+    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+    <title></title>
+    <style>
+      .emscripten { padding-right: 0; margin-left: auto; margin-right: auto; display: block; }
+      div.emscripten { text-align: center; }
+      /* the canvas *must not* have any border or padding, or mouse coords will be wrong */
+      canvas.emscripten { border: 0px none; }
+
+      .window {
+        position: absolute;
+        pointer-events: none;
+        z-index: 10;
+        background-color: black;
+        overflow: hidden;
+        width: 0;
+        height: 0;
+      }
+
+      .window-canvas {
+        position: absolute;
+        top: 0;
+        left: 0;
+        pointer-events: none;
+      }
+    </style>
+  </head>
+  <body style="margin: 0; padding: 0; width: 100%; height: 100%; overflow: hidden">
+  <div id="main-window"></div>
+
+  <div id="progress-container" class="centered">
+    <div id="progress-text">Loading...</div>
+    <div id="progress-bar">
+      <div id="progress-bar-position">
+      </div>
+    </div>
+  </div>
+
+  <div id="window-container"></div>
+  
+  <script>
+    var mainWindow = document.getElementById('main-window');
+    var statusElement = document.getElementById('progress-text');
+    var progressElement = document.getElementById('progress-bar-position');
+
+    var createCanvas = function () {
+      var canvas = document.createElement('canvas');
+      canvas.id = 'canvas';
+      canvas.style.display = 'none';
+      canvas.style.width = window.innerWidth + 'px';
+      canvas.style.height = window.innerHeight + 'px';
+      canvas.oncontextmenu = function () { event.preventDefault(); }
+      canvas.addEventListener("webglcontextlost", function (e) {
+        showError('WebGL context lost. You will need to reload the page.');
+        e.preventDefault();
+      }, false);
+
+      mainWindow.appendChild(canvas);
+
+      Module.canvas = canvas;
+    };
+
+    var onRuntimeInitialized = function () {
+      var canvas = Module.canvas;
+      canvas.style.display = 'block';
+    };
+
+    var Module = {
+      preRun: [createCanvas],
+      postRun: [],
+      print: function(text) {
+        if (arguments.length > 1)
+          text = Array.prototype.slice.call(arguments).join(' ');
+        console.log(text);
+      },
+      printErr: function(text) {
+        if (arguments.length > 1)
+          text = Array.prototype.slice.call(arguments).join(' ');
+        console.error(text);
+      },
+      setStatus: function(text) {
+        if (!Module.setStatus.last) Module.setStatus.last = { time: Date.now(), text: '' };
+        if (text === Module.setStatus.text) return;
+        var m = text.match(/([^(]+)\((\d+(\.\d+)?)\/(\d+)\)/);
+        if (m) {
+          text = m[1];
+          progressElement.style.width = m[2] / m[4] + '%';
+          progressElement.hidden = false;
+        } else {
+          progressElement.hidden = true;
+        }
+        statusElement.innerHTML = text;
+      },
+      totalDependencies: 0,
+      monitorRunDependencies: function(left) {
+        this.totalDependencies = Math.max(this.totalDependencies, left);
+        Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
+      },
+      onRuntimeInitialized: onRuntimeInitialized
+    };
+    Module.setStatus('Downloading...');
+    window.onerror = function() {
+      showError('Exception thrown, see JavaScript console');
+      Module.setStatus = function(text) {
+        if (text) Module.printErr('[post-exception status] ' + text);
+      };
+    };
+  </script>
+  <script async type="text/javascript" src="minimal_test.js"></script>
+  </body>
+</html>