claude-code: the sealed hand-over, the credentials write with the lineage rule, the identity read (hq to-be 40 WP2, in progress)

The parts of the agent module that hold whichever way the console is registered: X25519 +
HKDF + AES-GCM from Node's own library so the bundle carries no dependency; the predecessor's
lineage rule (rotation only if newer, a re-issue adopted, a switch regardless) with its
incidents as tests; an atomic 0600 write that strips any refresh token and keeps keys it does not
know; the account read from the agent's own state file. Manifest and renderer follow.

modules/claude-code/test/identity.test.ts

@@ -0,0 +1,19 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { mkdtempSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { readIdentity } from "../dist/identity.js";
+
+test("the account is read from the agent's state file", () => {
+  const p = join(mkdtempSync(join(tmpdir(), "cc-id-")), ".claude.json");
+  writeFileSync(p, JSON.stringify({ oauthAccount: { accountUuid: "u-1", emailAddress: "a@example.org" }, other: 2 }));
+  assert.deepEqual(readIdentity(p), { accountUuid: "u-1", emailAddress: "a@example.org", organizationUuid: undefined });
+});
+
+test("no state file, or no account in it, is no identity rather than a guess", () => {
+  assert.equal(readIdentity("/nonexistent/.claude.json"), null);
+  const p = join(mkdtempSync(join(tmpdir(), "cc-id-")), ".claude.json");
+  writeFileSync(p, "{}");
+  assert.equal(readIdentity(p), null);
+});