feat(wasm): suppress stale client completions

req: client_local/011\nreq: client_local/012\nreq: operations/003

hemx-build/src/lib.rs

@@ -1676,6 +1676,7 @@ fn known_hemx_attr(name: &str) -> bool {
             | "data-hemx-client-event"
             | "data-hemx-client-fallback"
             | "data-hemx-client-module"
+            | "data-hemx-client-policy"
             | "data-hemx-client-state-version"
             | "data-hemx-pending-class"
             | "data-hemx-indicator"
@@ -1728,6 +1729,14 @@ fn reject_invalid_hemx_attr_values(path: &Path, attrs: &[SurfaceAttribute]) -> i
                     "expected a non-empty client handler name",
                 ));
             }
+            "data-hemx-client-policy" if !matches!(value.trim(), "latest" | "drop") => {
+                return Err(invalid_hemx_value(
+                    path,
+                    &attr.name,
+                    value,
+                    "expected `latest` or `drop`",
+                ));
+            }
             "data-hemx-client-module" if !valid_client_module(value) => {
                 return Err(invalid_hemx_value(
                     path,