fix(test): match hashed runtime asset selector

Update the shared test selector to accept hemx-axum's content-hashed runtime script path instead of the old fixed /hemx.js path.

req: axum/005

req: test/001

hemx-test/src/lib.rs

@@ -233,7 +233,7 @@ pub fn document_title_selector() -> &'static str {
 /// Build a selector for the hemx runtime script without exposing its asset path in tests.
 /// req: test/001 req: dx/006
 pub fn runtime_script_selector() -> &'static str {
-    "script[src=\"/hemx.js\"]"
+    "script[src^=\"/hemx.\"][src$=\".js\"]"
 }
 
 /// Build a selector for any hemx root without spelling the attribute in tests.