feat: Add base HTML template and implement dashboard, logs, and service views

- Created a base HTML template for consistent layout across pages.
- Developed a dashboard page to display backup service metrics and statuses.
- Implemented a log viewer for detailed log file inspection.
- Added error handling page for better user experience during failures.
- Introduced service detail page to show specific service metrics and actions.
- Enhanced log filtering and viewing capabilities.
- Integrated auto-refresh functionality for real-time updates on metrics.
- Created integration and unit test scripts for backup metrics functionality.

templates/error.html

@@ -0,0 +1,33 @@
+{% extends "base.html" %}
+
+{% block title %}Error{% endblock %}
+
+{% block content %}
+<div class="container mt-5">
+    <div class="row justify-content-center">
+        <div class="col-md-6">
+            <div class="text-center">
+                <i class="fas fa-exclamation-triangle fa-5x text-warning mb-4"></i>
+                <h1 class="display-4">{{ error_code | default('Error') }}</h1>
+                <p class="lead">{{ error_message | default('An unexpected error occurred.') }}</p>
+                
+                {% if error_details %}
+                <div class="alert alert-danger text-start mt-4">
+                    <h6 class="alert-heading">Error Details:</h6>
+                    <pre class="mb-0">{{ error_details }}</pre>
+                </div>
+                {% endif %}
+                
+                <div class="mt-4">
+                    <a href="{{ url_for('index') }}" class="btn btn-primary me-2">
+                        <i class="fas fa-home me-1"></i>Go to Dashboard
+                    </a>
+                    <button onclick="history.back()" class="btn btn-outline-secondary">
+                        <i class="fas fa-arrow-left me-1"></i>Go Back
+                    </button>
+                </div>
+            </div>
+        </div>
+    </div>
+</div>
+{% endblock %}