fix: change default event montage grid columns from 5 to 2

Changed the default number of columns for event montage view from 5 to 2
for better initial viewing experience, especially on mobile and tablet devices.

Changes:
- Updated DEFAULT_SETTINGS.eventMontageGridCols from 5 to 2
- Updated test expectation to match new default

This provides a more reasonable default layout that works better across
different screen sizes while still allowing users to customize the column
count as needed.

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

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

Author: pliablepixels

app/src/stores/__tests__/settings.test.ts

@@ -14,7 +14,7 @@ describe('Settings Store', () => {
     expect(settings.viewMode).toBe('snapshot');
     expect(settings.snapshotRefreshInterval).toBe(3);
     expect(settings.montageGridRows).toBe(4);
-    expect(settings.eventMontageGridCols).toBe(5);
+    expect(settings.eventMontageGridCols).toBe(2);
     expect(settings.monitorDetailCycleSeconds).toBe(0);
     expect(settings.eventsThumbnailFit).toBe('contain');
   });

app/src/stores/settings.ts

@@ -88,7 +88,7 @@ const DEFAULT_SETTINGS: ProfileSettings = {
   eventMontageLayouts: {},
   montageGridRows: 4,
   montageGridCols: 4,
-  eventMontageGridCols: 5,
+  eventMontageGridCols: 2,
   montageIsFullscreen: false,
   montageFeedFit: 'contain',
   eventsViewMode: 'list',