feat(frontend): T44 setup FastAPI static files and templates

- Mount static files on /static endpoint
- Configure Jinja2Templates with directory structure
- Create base template with Pico.css, HTMX, Chart.js
- Create all template subdirectories (auth, dashboard, keys, tokens, profile, components)
- Create initial CSS and JS files
- Add tests for static files and templates configuration

Tests: 12 passing
Coverage: 100% on new configuration code

static/js/main.js

@@ -0,0 +1,49 @@
+// OpenRouter Monitor - Main JavaScript
+
+// HTMX Configuration
+document.addEventListener('DOMContentLoaded', function() {
+    // Configure HTMX to include CSRF token in requests
+    document.body.addEventListener('htmx:configRequest', function(evt) {
+        const csrfToken = document.querySelector('meta[name="csrf-token"]');
+        if (csrfToken) {
+            evt.detail.headers['X-CSRF-Token'] = csrfToken.content;
+        }
+    });
+    
+    // Auto-hide alerts after 5 seconds
+    const alerts = document.querySelectorAll('.alert:not(.alert-permanent)');
+    alerts.forEach(function(alert) {
+        setTimeout(function() {
+            alert.style.opacity = '0';
+            setTimeout(function() {
+                alert.remove();
+            }, 300);
+        }, 5000);
+    });
+});
+
+// Utility function to format currency
+function formatCurrency(amount) {
+    return new Intl.NumberFormat('en-US', {
+        style: 'currency',
+        currency: 'USD'
+    }).format(amount);
+}
+
+// Utility function to format date
+function formatDate(dateString) {
+    return new Intl.DateTimeFormat('en-US', {
+        year: 'numeric',
+        month: 'short',
+        day: 'numeric',
+        hour: '2-digit',
+        minute: '2-digit'
+    }).format(new Date(dateString));
+}
+
+// Confirmation dialog for destructive actions
+function confirmAction(message, callback) {
+    if (confirm(message)) {
+        callback();
+    }
+}