Fix Time Tracking header jump by standardizing container classes

- Replace time-tracking-container with page-container for consistency
- Update all timetrack pages to use standard page-container class
- Remove duplicate timetrack-container class references
- This ensures consistent header positioning across all pages

static/css/time-tracking.css

@@ -1,6 +1,6 @@
 /* Time Tracking Styles */
 
-/* Container */
+/* Container - Legacy support for old pages */
 .time-tracking-container {
     max-width: 1400px;
     margin: 0 auto;