Implement Studio root and placement capabilities on the replica graph (WI-10)

src/execution-world/reflection.ts

@@ -0,0 +1,28 @@
+import type { ValueType, WorkspaceRevision } from "../capability-model/types.js";
+import { ExecutionPlanError } from "./plan.js";
+const string: ValueType = { kind: "scalar", name: "string" };
+/** Narrow immutable installation metadata. No graph enumeration or live reflection. */
+export function portableReflectionType(selector: string): ValueType {
+  if (selector !== "presentations")
+    throw new ExecutionPlanError(
+      "UNSUPPORTED_PORTABLE_REFLECTION",
+      selector,
+      "Only checked presentation metadata is portable",
+    );
+  return {
+    kind: "list",
+    value: { kind: "record", fields: { id: string, subject: string, atoms: { kind: "list", value: string } } },
+  };
+}
+export function portableReflectionValue(workspace: WorkspaceRevision, selector: string) {
+  portableReflectionType(selector);
+  return (workspace.presentations ?? [])
+    .map((p) => ({
+      id: p.id,
+      subject: p.subject,
+      atoms: [
+        ...new Set(workspace.conformances.filter((c) => c.interfaceRevisionId === p.subject).map((c) => c.atomId)),
+      ].sort(),
+    }))
+    .sort((a, b) => a.id.localeCompare(b.id));
+}