Phase 1 of Custom DNS Provider Plugin Support: the /api/v1/dns-providers/types
endpoint now returns types dynamically from the dnsprovider.Global() registry
instead of a hardcoded list.
Backend handler queries registry for all provider types, metadata, and fields
Response includes is_built_in flag to distinguish plugins from built-ins
Frontend types updated with DNSProviderField interface and new response shape
Fixed flaky WAF exclusion test (isolated file-based SQLite DB)
Updated operator docs for registry-driven discovery and plugin installation
Refs: #461
77a020b4db