Support checked keyed relationships across portable operations and queries

test/fixtures/presentation-mount/queries/reader-inputs.graphql

@@ -0,0 +1,7 @@
+query ReaderState {
+  root {
+    states(all: 100) {
+      entries { key mapKey node { _camino { ref } page } }
+    }
+  }
+}

test/fixtures/presentation-mount/queries/reader-state.graphql

@@ -0,0 +1,7 @@
+query ReaderState($key: String!) {
+  root {
+    states(all: 100, where: {_camino: {mapKey: {eq: $key}}}) {
+      entries { key mapKey node { _camino { ref } page } }
+    }
+  }
+}

test/fixtures/presentation-mount/queries/reader-window.graphql

@@ -0,0 +1,7 @@
+query ReaderState($key: String!) {
+  root {
+    states(first: 100, where: {_camino: {mapKey: {eq: $key}}}) {
+      entries { key mapKey node { _camino { ref } page } }
+    }
+  }
+}