feat(dashboard): replace emojis with Font Awesome, add theme support, and styled dialogs

This commit implements three major improvements to the dashboard system:

1. **Font Awesome Icons for Tabs**
   - Replace emoji tab icons (📊, 🌍, 🎒) with Font Awesome classes
   - Update defaultLayout.js with fa-solid icon classes
   - Add automatic migration for existing saved dashboards with emoji icons
   - Implement migrateEmojiIcons() to convert old emoji icons on load
   - Update fallback icons throughout the system

2. **Custom Theme Support for Dashboard**
   - Replace all --SmartTheme* variables with --rpg-* variables
   - Ensure custom themes (sci-fi, fantasy, cyberpunk) apply to dashboard
   - Update CSS for tabs, buttons, dropdowns, modals, and widget cards
   - Dashboard now respects extension themes instead of main SillyTavern theme

3. **Styled Confirmation Dialogs**
   - Create confirmDialog.js with showConfirmDialog() and showAlertDialog()
   - Support three variants: danger (red), warning (yellow), info (blue)
   - Add keyboard navigation (Enter/Escape) and accessibility features
   - Replace all native confirm() and alert() calls with styled dialogs
   - Add confirmation dialog modal to dashboardTemplate.html

Files Modified:
- src/systems/dashboard/confirmDialog.js (NEW)
- src/systems/dashboard/dashboardManager.js
- src/systems/dashboard/defaultLayout.js
- src/systems/dashboard/tabManager.js
- src/systems/dashboard/dashboardIntegration.js
- src/systems/dashboard/editModeManager.js
- src/systems/dashboard/widgets/inventoryWidget.js
- src/systems/dashboard/dashboardTemplate.html
- style.css

src/systems/dashboard/dashboardIntegration.js

@@ -14,6 +14,7 @@ import { WidgetRegistry } from './widgetRegistry.js';
 import { generateDefaultDashboard } from './defaultLayout.js';
 import { TabScrollManager } from './tabScrollManager.js';
 import { HeaderOverflowManager } from './headerOverflowManager.js';
+import { showConfirmDialog } from './confirmDialog.js';
 
 // Widget imports
 import { registerUserInfoWidget } from './widgets/userInfoWidget.js';
@@ -224,9 +225,17 @@ function setupDashboardEventListeners(dependencies) {
     // Reset layout button
     const resetLayoutBtn = document.querySelector('#rpg-dashboard-reset-layout');
     if (resetLayoutBtn) {
-        resetLayoutBtn.addEventListener('click', () => {
+        resetLayoutBtn.addEventListener('click', async () => {
             if (dashboardManager) {
-                if (confirm('Reset dashboard to default layout? This will remove all widgets and reload the defaults.')) {
+                const confirmed = await showConfirmDialog({
+                    title: 'Reset Layout?',
+                    message: 'This will remove all widgets and reload the default layout. This action cannot be undone.',
+                    variant: 'danger',
+                    confirmText: 'Reset',
+                    cancelText: 'Cancel'
+                });
+
+                if (confirmed) {
                     console.log('[RPG Companion] Reset layout button clicked');
                     dashboardManager.resetLayout();
                 }