feat(axum): add concise interaction request dispatch

Wrap extracted interaction forms in an InteractionRequest with a concise dispatch path, add a handlers() helper, and move canonical examples off direct HandlerRegistry/InteractionForm plumbing.

req: axum_integration/003

req: ceremony/001

req: dx/003

req: examples/003

slhx-axum/tests/response.rs

@@ -2,9 +2,10 @@ use axum::http::{header, HeaderMap};
 use axum::response::IntoResponse;
 use scraper::{Html, Selector};
 use slhx_axum::{
-    runtime_js, DispatchRejection, EffectResponse, HandlerRegistry, InteractionForm,
-    InteractionFormRejection, PageMode, PageRequest, PageResponse, SLHX_CONTENT_TYPE,
-    SLHX_FINGERPRINT_HEADER, SLHX_PARTIAL_HEADER, SLHX_RUNTIME_CONTENT_TYPE, SLHX_TITLE_HEADER,
+    handlers, runtime_js, DispatchRejection, EffectResponse, HandlerRegistry, InteractionForm,
+    InteractionFormRejection, InteractionRequest, PageMode, PageRequest, PageResponse,
+    SLHX_CONTENT_TYPE, SLHX_FINGERPRINT_HEADER, SLHX_PARTIAL_HEADER, SLHX_RUNTIME_CONTENT_TYPE,
+    SLHX_TITLE_HEADER,
 };
 use slhx_core::{push, BuildFingerprint, Handle, SafeHtml, Slot};
 
@@ -139,6 +140,23 @@ fn interaction_form_preserves_hidden_csrf_fields_for_extractors() {
     assert!(form.fields().iter().any(|(name, _)| name == "csrf_token"));
 }
 
+#[test]
+fn interaction_request_dispatches_with_concise_handlers_helper() {
+    // req: axum_integration/003 req: ceremony/001 req: dx/003
+    let request = InteractionRequest::from(InteractionForm::for_handle(
+        Handle::<()>::new(7),
+        Vec::new(),
+    ));
+    let response = request
+        .dispatch(handlers(BuildFingerprint(4)).register_handle(Handle::<()>::new(7), |_| {
+            Slot::<String>::new(3).text("ok")
+        }))
+        .unwrap();
+
+    assert_eq!(response.batch.fingerprint, BuildFingerprint(4));
+    assert_eq!(response.batch.ops, vec![Slot::<String>::new(3).text("ok")]);
+}
+
 #[test]
 fn handler_registry_dispatches_by_checked_handle() {
     // req: ceremony/004 req: public_api/001