fix(db): comprehensive symbol recovery + safety fixes

prisma/seed.js

@@ -115,15 +115,10 @@ async function main() {
   // Deleting would either break references (tenant symbols become 404s)
   // or cascade-delete tenant symbols. Instead we upsert by fileKey.
 
-  // Clean up empty global categories
-  const oldGlobalCats = await prisma.iconCategory.findMany({ where: { tenantId: null } })
-  for (const oldCat of oldGlobalCats) {
-    const remaining = await prisma.iconAsset.count({ where: { categoryId: oldCat.id } })
-    if (remaining === 0) {
-      await prisma.iconCategory.delete({ where: { id: oldCat.id } }).catch(() => {})
-    }
-  }
-  // Create new global categories
+  // NOTE: We intentionally do NOT delete any icon categories here.
+  // Tenant-specific categories may reference them, and deleting could
+  // orphan user data. Empty categories are harmless.
+  // Create or update global categories
   const catMap = {}
   for (const def of catDefs) {
     const cat = await prisma.iconCategory.upsert({