feat(runtime): add URL-state GET navigation

hemx-build/src/lib.rs

@@ -1597,6 +1597,7 @@ fn known_hemx_attr(name: &str) -> bool {
             | "data-hemx-disable-while-pending"
             | "data-hemx-policy"
             | "data-hemx-nav"
+            | "data-hemx-history"
             | "data-hemx-boost"
             | "data-hemx-error-for"
             | "data-hemx-error"
@@ -1619,6 +1620,14 @@ fn reject_invalid_hemx_attr_values(path: &Path, attrs: &[SurfaceAttribute]) -> i
                     "expected one of `latest`, `queue`, `drop`, or `parallel`",
                 ));
             }
+            "data-hemx-history" if !matches!(value.trim(), "" | "push" | "replace") => {
+                return Err(invalid_hemx_value(
+                    path,
+                    &attr.name,
+                    value,
+                    "expected `push`, `replace`, or empty for the default push behavior",
+                ));
+            }
             "data-hemx-on" if !valid_event_list(value) => {
                 return Err(invalid_hemx_value(
                     path,
@@ -2820,6 +2829,12 @@ fn main() {{
                 "data-hemx-interval",
                 "1s",
             ),
+            (
+                "history",
+                r#"<form method="get" action="/search" data-hemx-history="append"><input name="q"></form>"#,
+                "data-hemx-history",
+                "replace",
+            ),
             (
                 "event",
                 r#"<button data-hemx-handle="save" data-hemx-on="keydown">Save</button>"#,