bdb3ca856f
- New config/credential_store.go: persistent credential storage (credentials.json) - New API: CRUD for DNS credentials + credential-types endpoint - Certificate model now supports credential_id reference - Create certificate auto-resolves credential_id to DNS config - New Vue page: Credentials.vue for managing saved DNS keys - CertCreate.vue: select existing credential or manual input + save as new - Secrets masked in API responses, never exposed in list