Add HyperFrames skills

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011h6NB8JQtfPc6eRCefEzBB

.agents/skills/media-use/scripts/lib/media-home.mjs

@@ -0,0 +1,20 @@
+import { homedir } from "node:os";
+import { join } from "node:path";
+
+// The one owner of where the person's media library lives. This repo's test runs set
+// HYPERFRAMES_MEDIA_HOME_REQUIRED, so a test that forgot HYPERFRAMES_MEDIA_HOME fails instead
+// of writing fixtures into the media library apps list as the person's own files.
+export function mediaHome() {
+  const override = process.env.HYPERFRAMES_MEDIA_HOME;
+  if (override) return override;
+  if (process.env.HYPERFRAMES_MEDIA_HOME_REQUIRED) {
+    throw new Error(
+      "media-use: a test reached the real ~/.media; set HYPERFRAMES_MEDIA_HOME to a temp dir",
+    );
+  }
+  return homedir();
+}
+
+export function globalMediaDir() {
+  return join(mediaHome(), ".media");
+}