fix(dashboard): resolve widget sizing and detection issues

Issue 1: PresentCharacters widget too small with gaps
- Increase height from h:3 to h:4 in defaultLayout.js
- Widget's defaultSize is h:2 but layout had h:3, creating mismatch
- Now properly fills vertical space without gaps

Issue 2: Recent Events not appearing in reset/auto-arrange
Root cause: previousTrackerConfig starts as null, preventing widget detection

Fixes:
- Initialize previousTrackerConfig on dashboard load (dashboardIntegration.js)
  - Deep clone trackerConfig after dashboard init
  - Enables detectConfigChanges() to work on first load
- Reset previousTrackerConfig to null in resetLayout() (dashboardManager.js)
  - Ensures fresh detection after layout reset
  - Prevents stale comparison data

Verified: Recent Events enabled by default in tracker config (state.js:95)

Result:
✅ PresentCharacters fills space properly
✅ Recent Events appears in reset layout
✅ Recent Events appears in auto-arrange
✅ Tracker editor enable/disable now works correctly

src/systems/dashboard/dashboardIntegration.js

@@ -104,6 +104,14 @@ export async function initializeDashboard(dependencies) {
         dashboardManager.setDefaultLayout(defaultLayout);
         console.log('[RPG Companion] Default layout set with', defaultLayout.tabs.length, 'tabs');
 
+        // Initialize previousTrackerConfig to enable widget detection on first load
+        // Without this, detectConfigChanges() returns [] because oldConfig is null
+        const settings = dependencies.getExtensionSettings();
+        if (settings?.trackerConfig && dashboardManager) {
+            dashboardManager.previousTrackerConfig = JSON.parse(JSON.stringify(settings.trackerConfig));
+            console.log('[RPG Companion] Initialized previousTrackerConfig for widget detection');
+        }
+
         // Set up dashboard event listeners
         setupDashboardEventListeners(dependencies);