T-1: a TypeScript part reads a definition's callers as the format's list

Text and a bare name are refused naming the verb, as the Go reader does.

Builds: design 47 G §196, §336, §392

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

src/callers/index.ts

@@ -174,3 +174,25 @@ export function parseConfiguredVerbCallers(raw: unknown, verbs: readonly string[
   if (typeof raw === "string") return parseVerbCallers(raw, verbs, defaults);
   return parseVerbCallers(JSON.stringify(raw), verbs, defaults);
 }
+
+/** The kinds of name a seat definition's `callers` entry may be besides `seat:<seat>`, `module:<module>` and `holder:<seat>@same-node` (design 47 G §336, §392). */
+const callerWords = ["operator", "healers", "persons", "sessions", "invokers"];
+const callerForm = /^(seat:[a-z][a-z0-9-]*|module:[a-z][a-z0-9-]*|holder:[a-z][a-z0-9-]*@same-node)$/;
+
+/**
+ * The callers a seat definition names for a verb or an accepted kind (design 47 G §336, §392): a list of entries, each
+ * one of the forms the format knows. Text is refused naming the verb, and so is an entry that is no form (a bare name
+ * among them), as the Go reader does.
+ */
+export function readDefinitionCallers(verb: string, value: unknown): readonly string[] {
+  if (typeof value === "string") {
+    throw new Error(`${verb}: callers are text ("${value}"): a definition gives its callers as a list`);
+  }
+  if (!Array.isArray(value)) throw new Error(`${verb}: callers is not a list of entries`);
+  for (const e of value) {
+    if (typeof e !== "string" || !(callerWords.includes(e) || callerForm.test(e))) {
+      throw new Error(`${verb}: the callers entry ${JSON.stringify(e)} is none of ${callerWords.join(", ")}, seat:<seat>, module:<module> and holder:<seat>@same-node`);
+    }
+  }
+  return value as string[];
+}