feat: Add EU cookie banner and user settings page

Cookie Banner:
- GDPR-compliant consent banner
- Shows on first visit, stores consent in localStorage
- Two options: Accept All / Only Essential
- Dark theme with smooth animations

Settings Page (/settings):
- Profile form: display name editing
- Password change with validation
- Cookie settings info section
- Privacy links and account info

New files:
- src/hooks/useCookieConsent.ts
- src/components/CookieBanner.tsx
- src/components/ProfileForm.tsx
- src/components/PasswordChangeForm.tsx
- src/services/profile-actions.ts
- src/app/settings/page.tsx

src/hooks/useCookieConsent.ts

@@ -0,0 +1,69 @@
+'use client';
+
+import { useState, useEffect, useCallback } from 'react';
+
+export type ConsentLevel = 'all' | 'essential' | null;
+
+interface CookieConsent {
+    level: ConsentLevel;
+    timestamp: string;
+}
+
+const CONSENT_KEY = 'cookie_consent';
+
+/**
+ * Hook for managing GDPR-compliant cookie consent
+ */
+export function useCookieConsent() {
+    const [consent, setConsent] = useState<CookieConsent | null>(null);
+    const [isLoading, setIsLoading] = useState(true);
+
+    // Load consent from localStorage on mount
+    useEffect(() => {
+        try {
+            const stored = localStorage.getItem(CONSENT_KEY);
+            if (stored) {
+                setConsent(JSON.parse(stored));
+            }
+        } catch (e) {
+            console.warn('[CookieConsent] Failed to load consent:', e);
+        }
+        setIsLoading(false);
+    }, []);
+
+    // Accept all cookies (essential + functional)
+    const acceptAll = useCallback(() => {
+        const newConsent: CookieConsent = {
+            level: 'all',
+            timestamp: new Date().toISOString(),
+        };
+        localStorage.setItem(CONSENT_KEY, JSON.stringify(newConsent));
+        setConsent(newConsent);
+    }, []);
+
+    // Accept only essential cookies
+    const acceptEssential = useCallback(() => {
+        const newConsent: CookieConsent = {
+            level: 'essential',
+            timestamp: new Date().toISOString(),
+        };
+        localStorage.setItem(CONSENT_KEY, JSON.stringify(newConsent));
+        setConsent(newConsent);
+    }, []);
+
+    // Reset consent (for settings page)
+    const resetConsent = useCallback(() => {
+        localStorage.removeItem(CONSENT_KEY);
+        setConsent(null);
+    }, []);
+
+    return {
+        hasConsent: consent !== null,
+        consentLevel: consent?.level ?? null,
+        consentTimestamp: consent?.timestamp ?? null,
+        isLoading,
+        acceptAll,
+        acceptEssential,
+        resetConsent,
+    };
+}