v0.32.4

docs/API.md

@@ -397,6 +397,14 @@ and rust_proxy_http3_requests_total. See source `metrics.rs` for exact HELP/type
 contracts and INTEGRATIONS_040.md for configuration examples.
 
 
+## 0.32.4 backend Host and HTTP/2 authority
+
+Existing backend `preserve_host` is now valid for all `protocol` values:
+`http1`, `auto`, `http2` and `h2`. HTTP/2 :authority follows the request Host,
+while socket/DNS use the configured origin and TLS SNI uses
+`tls_server_name` if present. No new JSON fields, endpoints, database migration
+or extra retries. HTTP health checks maintain their own Host override.
+
 ## 0.32.3 Overview registry and compatible upstream modes
 
 The backend `protocol` wire values are `http1` (default), `auto`, `http2`