add simulator mode to desktop designer for testing apps

- Add --simulator flag to launch home screen showing discovered apps
- Create app discovery system to scan test-apps/ directory
- Build simulator home screen with dark phone-like UI
- Add Lua API: simulator.launchApp, simulator.goHome, simulator.getApps
- ESC key returns to home when inside an app
- Apps displayed with icons in grid layout

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

designer/assets/simulator/home.rcss

@@ -0,0 +1,154 @@
+/* Simulator Home Screen Styles */
+
+body {
+    font-family: LatoLatin;
+    background-color: #1a1a2e;
+    color: #ffffff;
+    width: 100%;
+    height: 100%;
+    margin: 0;
+    padding: 0;
+    display: flex;
+    flex-direction: column;
+}
+
+/* Status Bar */
+.status-bar {
+    display: flex;
+    flex-direction: row;
+    justify-content: space-between;
+    align-items: center;
+    height: 24dp;
+    padding: 0 12dp;
+    background-color: #0f0f1a;
+    font-size: 12dp;
+    color: #cccccc;
+}
+
+.status-time {
+    font-weight: bold;
+}
+
+.status-icons {
+    display: flex;
+    flex-direction: row;
+    gap: 8dp;
+}
+
+.status-wifi, .status-battery {
+    font-size: 10dp;
+    color: #4ade80;
+}
+
+/* Home Content */
+.home-content {
+    flex: 1;
+    padding: 16dp;
+    overflow: auto;
+}
+
+.home-header {
+    text-align: center;
+    margin-bottom: 24dp;
+}
+
+.home-header h1 {
+    font-size: 24dp;
+    font-weight: bold;
+    margin: 0 0 4dp 0;
+    color: #ffffff;
+}
+
+.home-header .subtitle {
+    font-size: 14dp;
+    color: #888888;
+    margin: 0;
+}
+
+/* App Grid */
+.app-grid {
+    display: flex;
+    flex-direction: row;
+    flex-wrap: wrap;
+    gap: 16dp;
+    justify-content: center;
+}
+
+.no-apps {
+    text-align: center;
+    color: #666666;
+    padding: 32dp;
+}
+
+.no-apps p {
+    margin: 8dp 0;
+}
+
+.no-apps .hint {
+    font-size: 12dp;
+    color: #555555;
+}
+
+/* App Icon */
+.app-icon {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    width: 80dp;
+    cursor: pointer;
+}
+
+.app-icon:hover .app-icon-image {
+    transform: scale(1.1);
+    background-color: #3d3d5c;
+}
+
+.app-icon-image {
+    width: 56dp;
+    height: 56dp;
+    border-radius: 12dp;
+    background-color: #2d2d44;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    overflow: hidden;
+    transition: transform 0.1s, background-color 0.1s;
+}
+
+.app-icon-image img {
+    width: 48dp;
+    height: 48dp;
+}
+
+.app-icon-placeholder {
+    font-size: 24dp;
+    color: #888888;
+}
+
+.app-icon-label {
+    font-size: 11dp;
+    color: #cccccc;
+    margin-top: 6dp;
+    text-align: center;
+    max-width: 80dp;
+    overflow: hidden;
+    white-space: nowrap;
+}
+
+/* Navigation Bar */
+.nav-bar {
+    display: flex;
+    flex-direction: row;
+    justify-content: center;
+    gap: 24dp;
+    height: 40dp;
+    background-color: #0f0f1a;
+    align-items: center;
+    border-top-width: 1dp;
+    border-top-color: #2d2d44;
+}
+
+.nav-hint {
+    font-size: 11dp;
+    color: #666666;
+}