feat: Add NPV comparison and distribution charts to reporting

- Implemented NPV comparison chart generation using Plotly in ReportingService.
- Added distribution histogram for Monte Carlo results.
- Updated reporting templates to include new charts and improved layout.
- Created new settings and currencies management pages.
- Enhanced sidebar navigation with dynamic URL handling.
- Improved CSS styles for chart containers and overall layout.
- Added new simulation and theme settings pages with placeholders for future features.

templates/theme_settings.html

@@ -0,0 +1,31 @@
+{% extends "base.html" %}
+{% block title %}{{ title }} | CalMiner{% endblock %}
+
+{% block content %}
+  <div class="page-header">
+    <div>
+      <h1>{{ title }}</h1>
+      <p class="page-subtitle">Customize the visual appearance of the application.</p>
+    </div>
+  </div>
+
+  <div class="settings-grid">
+    <div class="settings-card">
+      <h2>Color Theme</h2>
+      <p>Select your preferred color scheme.</p>
+      <p class="settings-card-note">Theme customization coming soon</p>
+    </div>
+
+    <div class="settings-card">
+      <h2>Layout Options</h2>
+      <p>Configure sidebar and navigation preferences.</p>
+      <p class="settings-card-note">Layout options coming soon</p>
+    </div>
+
+    <div class="settings-card">
+      <h2>Accessibility</h2>
+      <p>Adjust settings for better accessibility.</p>
+      <p class="settings-card-note">Accessibility settings coming soon</p>
+    </div>
+  </div>
+{% endblock %}