Remove unnecessary IONOS field name migration

The wrong field name only existed for one commit before the fix, and
the only affected user already re-entered their credentials.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/db.ts

@@ -301,48 +301,10 @@ function runCloudflareToProviderMigration() {
   db.insert(settingsTable).values({ key: "dns_provider_migrated", value: "true", updatedAt: now }).run();
 }
 
-/**
- * One-time migration: rename IONOS DNS credential key from the old
- * `api_token` to the correct `auth_api_token` expected by the libdns module.
- * Idempotent — skips if the key has already been renamed or never existed.
- */
-function runIonosFieldNameMigration() {
-  if (sqlitePath === ":memory:") return;
-
-  const { settings: settingsTable } = schema;
-
-  const flag = db.select().from(settingsTable).where(eq(settingsTable.key, "ionos_field_migrated")).get();
-  if (flag) return;
-
-  const row = db.select().from(settingsTable).where(eq(settingsTable.key, "dns_provider")).get();
-  if (row) {
-    try {
-      const parsed = JSON.parse(row.value) as { providers?: Record<string, Record<string, string>>; default?: string };
-      const ionos = parsed.providers?.ionos;
-      if (ionos && "api_token" in ionos && !("auth_api_token" in ionos)) {
-        ionos.auth_api_token = ionos.api_token;
-        delete ionos.api_token;
-        const now = new Date().toISOString();
-        db.update(settingsTable)
-          .set({ value: JSON.stringify(parsed), updatedAt: now })
-          .where(eq(settingsTable.key, "dns_provider"))
-          .run();
-        console.log("Migrated IONOS DNS provider field: api_token -> auth_api_token");
-      }
-    } catch (e) {
-      console.warn("Failed to migrate IONOS field name:", e);
-    }
-  }
-
-  const now = new Date().toISOString();
-  db.insert(settingsTable).values({ key: "ionos_field_migrated", value: "true", updatedAt: now }).run();
-}
-
 try {
   runBetterAuthDataMigration();
   runEnvProviderSync();
   runCloudflareToProviderMigration();
-  runIonosFieldNameMigration();
 } catch (error) {
   console.warn("Better Auth data migration warning:", error);
 }