Add skip logic to migration scripts to prevent re-running

scripts/migrate-release-years.mjs

@@ -122,6 +122,18 @@ async function getReleaseYear(artist, title) {
 // --- Migration Logic ---
 
 async function migrate() {
+    // Check if migration already ran
+    const flagPath = path.join(process.cwd(), '.release-years-migrated');
+    try {
+        const { access } = await import('fs/promises');
+        await access(flagPath);
+        console.log('✅ Release year migration already completed (flag file exists). Skipping...');
+        await prisma.$disconnect();
+        return;
+    } catch {
+        // Flag file doesn't exist, proceed with migration
+    }
+
     console.log('🎵 Starting release year migration...');
     console.log('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━');