feat: implement iTunes API for release year detection and bulk refresh

app/admin/page.tsx

@@ -1604,6 +1604,74 @@ export default function AdminPage() {
                 >
                     ☢️ Rebuild Database
                 </button>
+
+                <div style={{ marginTop: '1rem', borderTop: '1px solid #eee', paddingTop: '1rem' }}>
+                    <p style={{ marginBottom: '1rem', color: '#666' }}>
+                        Update release years for all songs using the iTunes API. This will overwrite existing years.
+                    </p>
+                    <button
+                        onClick={async () => {
+                            if (window.confirm('This will scan all songs and overwrite their release years using data from iTunes. This process may take a while.\n\nContinue?')) {
+                                try {
+                                    let offset = 0;
+                                    let hasMore = true;
+                                    let totalUpdated = 0;
+                                    let totalSkipped = 0;
+                                    let totalFailed = 0;
+                                    let totalProcessed = 0;
+                                    let totalSongs = 0;
+
+                                    setMessage('Initializing release year refresh...');
+
+                                    while (hasMore) {
+                                        const res = await fetch('/api/admin/refresh-years', {
+                                            method: 'POST',
+                                            headers: getAuthHeaders(),
+                                            body: JSON.stringify({ offset, limit: 10 }) // Process 10 at a time
+                                        });
+
+                                        if (!res.ok) {
+                                            throw new Error('Batch request failed');
+                                        }
+
+                                        const data = await res.json();
+
+                                        totalUpdated += data.updated;
+                                        totalSkipped += data.skipped;
+                                        totalFailed += data.failed;
+                                        totalProcessed += data.processed;
+                                        totalSongs = data.total;
+                                        hasMore = data.hasMore;
+                                        offset = data.nextOffset;
+
+                                        setMessage(`Processing... ${totalProcessed} / ${totalSongs} songs.\nUpdated: ${totalUpdated} | Skipped: ${totalSkipped} | Failed: ${totalFailed}`);
+                                    }
+
+                                    const finalMsg = `✅ Completed!\nTotal Processed: ${totalProcessed}\nUpdated: ${totalUpdated}\nSkipped: ${totalSkipped}\nFailed: ${totalFailed}`;
+                                    alert(finalMsg);
+                                    setMessage(finalMsg);
+                                    fetchSongs(); // Refresh the table
+
+                                } catch (e) {
+                                    console.error(e);
+                                    alert('Process failed due to network error or timeout.');
+                                    setMessage('Refresh failed.');
+                                }
+                            }
+                        }}
+                        style={{
+                            padding: '0.75rem 1.5rem',
+                            background: '#f59e0b',
+                            color: 'white',
+                            border: 'none',
+                            borderRadius: '0.25rem',
+                            cursor: 'pointer',
+                            fontWeight: 'bold'
+                        }}
+                    >
+                        🔄 Refresh Release Years (iTunes)
+                    </button>
+                </div>
             </div>
         </div>
     );