test(axum): exercise interaction helper path

Move public axum response tests off direct HandlerRegistry construction so the checked test surface follows interactions()/on() just like canonical examples.

req: axum_integration/003

req: ceremony/001

req: dx/003

slhx-axum/tests/response.rs

@@ -2,7 +2,7 @@ use axum::http::{header, HeaderMap};
 use axum::response::IntoResponse;
 use scraper::{Html, Selector};
 use slhx_axum::{
-    interactions, runtime_js, DispatchRejection, EffectResponse, HandlerRegistry, InteractionForm,
+    interactions, runtime_js, DispatchRejection, EffectResponse, InteractionForm,
     InteractionFormRejection, InteractionRequest, PageMode, PageRequest, PageResponse,
     SLHX_CONTENT_TYPE, SLHX_FINGERPRINT_HEADER, SLHX_PARTIAL_HEADER, SLHX_RUNTIME_CONTENT_TYPE,
     SLHX_TITLE_HEADER,
@@ -169,16 +169,19 @@ fn interaction_request_dispatches_with_concise_handlers_helper() {
 }
 
 #[test]
-fn handler_registry_dispatches_by_checked_handle() {
+fn interactions_dispatch_by_checked_handle() {
     // req: ceremony/004 req: public_api/001
     let title = Slot::<String>::new(7);
     let create = Handle::<()>::new(42);
-    let registry = HandlerRegistry::new(BuildFingerprint(123)).register_handle(create, move |form| {
-        title.text(form.value("title").unwrap_or(""))
-    });
+    let request = InteractionRequest::from(InteractionForm::for_handle(
+        create,
+        [("title".into(), "Hello".into())],
+    ));
 
-    let response = registry
-        .dispatch(InteractionForm::for_handle(create, [("title".into(), "Hello".into())]))
+    let response = request
+        .dispatch(interactions(BuildFingerprint(123)).on(create, move |form| {
+            title.text(form.value("title").unwrap_or(""))
+        }))
         .unwrap();
 
     assert_eq!(response.batch.fingerprint, BuildFingerprint(123));
@@ -186,11 +189,11 @@ fn handler_registry_dispatches_by_checked_handle() {
 }
 
 #[test]
-fn handler_registry_rejects_unknown_handle_ids() {
-    let registry = HandlerRegistry::new(BuildFingerprint(123));
+fn interactions_reject_unknown_handle_ids() {
+    let request = InteractionRequest::from(InteractionForm::new(9, []));
 
     assert_eq!(
-        registry.dispatch(InteractionForm::new(9, [])).unwrap_err(),
+        request.dispatch(interactions(BuildFingerprint(123))).unwrap_err(),
         DispatchRejection::UnknownHandle(9)
     );
 }