feat(media-use): usage telemetry for HeyGen conversion (#2130)

skills/media-use/audio/scripts/lib/heygen.mjs

@@ -69,6 +69,17 @@ export function heygenCredential() {
   return null;
 }
 
+// → "oauth" | "api_key" | null. Same oauth-vs-api-key check heygenAuthHeaders()
+// makes internally, exposed on its own so callers that only need to *tag* the
+// auth path (telemetry) don't have to parse headers back apart. Never throws:
+// no credential (or an expired one) is just `null`, same as a fresh resolve
+// with nothing to tag.
+export function heygenAuthMethod() {
+  const cred = heygenCredential();
+  if (!cred?.headers) return null;
+  return "Authorization" in cred.headers ? "oauth" : "api_key";
+}
+
 // → auth headers object, or throw with a fix hint.
 export function heygenAuthHeaders() {
   const cred = heygenCredential();

skills/media-use/audio/scripts/lib/heygen.test.mjs

@@ -3,7 +3,7 @@ import assert from "node:assert/strict";
 import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { heygenAuthHeaders } from "./heygen.mjs";
+import { heygenAuthHeaders, heygenAuthMethod } from "./heygen.mjs";
 
 function withCleanHeygenEnv(fn) {
   const previousApiKey = process.env.HEYGEN_API_KEY;
@@ -58,3 +58,43 @@ test("heygenAuthHeaders tags OAuth requests as CLI traffic", () => {
     }
   });
 });
+
+test("heygenAuthMethod returns api_key for an env API key, without tagging headers", () => {
+  withCleanHeygenEnv(() => {
+    process.env.HEYGEN_API_KEY = "hg_test";
+    assert.equal(heygenAuthMethod(), "api_key");
+  });
+});
+
+test("heygenAuthMethod returns oauth for a live OAuth credential", () => {
+  withCleanHeygenEnv(() => {
+    const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
+    try {
+      process.env.HEYGEN_CONFIG_DIR = dir;
+      writeFileSync(
+        join(dir, "credentials"),
+        JSON.stringify({
+          oauth: {
+            access_token: "at_test",
+            expires_at: "2099-01-01T00:00:00Z",
+          },
+        }),
+      );
+      assert.equal(heygenAuthMethod(), "oauth");
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});
+
+test("heygenAuthMethod returns null with no credential at all", () => {
+  withCleanHeygenEnv(() => {
+    const dir = mkdtempSync(join(tmpdir(), "heygen-cred-"));
+    try {
+      process.env.HEYGEN_CONFIG_DIR = dir; // no credentials file written
+      assert.equal(heygenAuthMethod(), null);
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  });
+});