feat: Enhance Game component with extra puzzles feature

- Introduce requiredDailyKeys to track daily puzzle completion across genres.
- Implement logic to show an ExtraPuzzlesPopover when all daily puzzles are completed.
- Add localized messages for extra puzzles in both English and German.
- Update GenrePage and Home components to pass requiredDailyKeys to the Game component.

components/ExtraPuzzlesPopover.tsx

@@ -0,0 +1,98 @@
+'use client';
+
+import { useTranslations, useLocale } from 'next-intl';
+import type { ExternalPuzzle } from '@/lib/externalPuzzles';
+
+interface ExtraPuzzlesPopoverProps {
+    puzzle: ExternalPuzzle;
+    onClose: () => void;
+}
+
+export default function ExtraPuzzlesPopover({ puzzle, onClose }: ExtraPuzzlesPopoverProps) {
+    const t = useTranslations('ExtraPuzzles');
+    const locale = useLocale();
+
+    const name = locale === 'de' ? puzzle.nameDe : puzzle.nameEn;
+
+    const handleClick = () => {
+        if (typeof window !== 'undefined' && window.plausible) {
+            window.plausible('extra_puzzles_click', {
+                props: {
+                    partner: puzzle.id,
+                    url: puzzle.url,
+                },
+            });
+        }
+        onClose();
+    };
+
+    return (
+        <div
+            style={{
+                position: 'fixed',
+                bottom: '1.5rem',
+                right: '1.5rem',
+                zIndex: 1100,
+                maxWidth: '320px',
+                boxShadow: '0 10px 30px rgba(0,0,0,0.25)',
+                borderRadius: '0.75rem',
+                background: 'white',
+                padding: '1rem 1.25rem',
+                display: 'flex',
+                flexDirection: 'column',
+                gap: '0.75rem',
+            }}
+        >
+            <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', gap: '0.5rem' }}>
+                <h3 style={{ margin: 0, fontSize: '1rem', fontWeight: 700 }}>
+                    {t('title')}
+                </h3>
+                <button
+                    onClick={onClose}
+                    aria-label={t('close')}
+                    style={{
+                        border: 'none',
+                        background: 'transparent',
+                        cursor: 'pointer',
+                        fontSize: '1.1rem',
+                        lineHeight: 1,
+                        color: '#6b7280',
+                    }}
+                >
+                    ×
+                </button>
+            </div>
+
+            <p style={{ margin: 0, fontSize: '0.9rem', color: '#4b5563' }}>
+                {t('message', { name })}
+            </p>
+
+            <a
+                href={puzzle.url}
+                target="_blank"
+                rel="noopener noreferrer"
+                onClick={handleClick}
+                style={{
+                    display: 'inline-flex',
+                    alignItems: 'center',
+                    justifyContent: 'center',
+                    gap: '0.4rem',
+                    marginTop: '0.25rem',
+                    padding: '0.5rem 0.75rem',
+                    borderRadius: '999px',
+                    border: 'none',
+                    background: 'linear-gradient(135deg, #4f46e5, #ec4899)',
+                    color: 'white',
+                    fontSize: '0.9rem',
+                    fontWeight: 600,
+                    textDecoration: 'none',
+                    cursor: 'pointer',
+                }}
+            >
+                {t('cta', { name })}
+            </a>
+        </div>
+    );
+}
+
+