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/settings.html

@@ -0,0 +1,41 @@
+{% extends "base.html" %}
+{% block title %}{{ title }} | CalMiner{% endblock %}
+
+{% block content %}
+  <div class="page-header">
+    <div>
+      <h1>{{ title }}</h1>
+      <p class="page-subtitle">Configure application settings and preferences.</p>
+    </div>
+  </div>
+
+  <div class="settings-grid">
+    <div class="settings-card">
+      <h2>Theme Settings</h2>
+      <p>Customize the appearance and color scheme of the application.</p>
+      <div class="page-actions">
+        <a href="{{ request.url_for('ui.theme_settings') }}" class="button">Configure Themes</a>
+      </div>
+    </div>
+
+    <div class="settings-card">
+      <h2>Currency Management</h2>
+      <p>Manage currency settings and exchange rates.</p>
+      <div class="page-actions">
+        <a href="{{ request.url_for('ui.currencies') }}" class="button">Manage Currencies</a>
+      </div>
+    </div>
+
+    <div class="settings-card">
+      <h2>User Preferences</h2>
+      <p>Configure personal preferences and defaults.</p>
+      <p class="settings-card-note">Coming soon</p>
+    </div>
+
+    <div class="settings-card">
+      <h2>System Configuration</h2>
+      <p>Advanced system settings and maintenance options.</p>
+      <p class="settings-card-note">Coming soon</p>
+    </div>
+  </div>
+{% endblock %}