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

templates/manage_project_tasks.html

@@ -1,7 +1,7 @@
 {% extends "layout.html" %}
 
 {% block content %}
-<div class="page-container timetrack-container">
+<div class="page-container">
     <div class="page-header task-header">
         <div class="project-info">
             <h2>Tasks for Project: {{ project.code }} - {{ project.name }}</h2>