feat(core): compose effect collections

Support Vec<T: IntoEffect> and [T; N] batches so dynamic reusable partial updates compose inside the existing effect model without a broad IntoIterator blanket impl.

req: canonical_authoring/003

hemx-core/src/lib.rs

@@ -850,6 +850,22 @@ impl<T: IntoEffect> IntoEffect for Option<T> {
     }
 }
 
+impl<T: IntoEffect> IntoEffect for Vec<T> {
+    fn append_to(self, ops: &mut Vec<Effect>) {
+        for effect in self {
+            effect.append_to(ops);
+        }
+    }
+}
+
+impl<T: IntoEffect, const N: usize> IntoEffect for [T; N] {
+    fn append_to(self, ops: &mut Vec<Effect>) {
+        for effect in self {
+            effect.append_to(ops);
+        }
+    }
+}
+
 macro_rules! impl_tuple_into_effect {
     ($($name:ident $idx:tt),+) => {
         impl<$($name),+> IntoEffect for ($($name,)+)

hemx-core/tests/effect_batch.rs

@@ -38,6 +38,30 @@ fn optional_effects_compose_into_batches() {
     assert_eq!(batch.ops[0], count.text(2));
 }
 
+#[test]
+fn effect_collections_compose_into_batches() {
+    // req: canonical_authoring/003
+    let rows = KeyedSlot::<u64, String>::new(2);
+    let summary = Slot::<u32>::new(3);
+    let notice = Slot::<String>::new(4);
+
+    let dynamic_rows = [7, 8]
+        .into_iter()
+        .map(|id| rows.replace_text(id, format!("todo {id}")))
+        .collect::<Vec<_>>();
+    let fixed_notices = [notice.text("Saved"), notice.text("Synced")];
+
+    let batch =
+        (dynamic_rows, Some(summary.text(2)), fixed_notices).into_batch(BuildFingerprint(42));
+
+    assert_eq!(batch.ops.len(), 5);
+    assert_eq!(batch.ops[0], rows.replace_text(7, String::from("todo 7")));
+    assert_eq!(batch.ops[1], rows.replace_text(8, String::from("todo 8")));
+    assert_eq!(batch.ops[2], summary.text(2));
+    assert_eq!(batch.ops[3], notice.text("Saved"));
+    assert_eq!(batch.ops[4], notice.text("Synced"));
+}
+
 #[test]
 fn keyed_slot_replace_uses_scoped_resource_ref() {
     let todos = KeyedSlot::<u64, String>::new(9);