the finances skeleton — repo, prefix and permission key, before any feature

Published empty on purpose: identity is the expensive part to change later, the
feature is the cheap part to add. One route, two placeholder panels, no tables and
no sidecar.

api/router.ts

@@ -0,0 +1,6 @@
+import { createRouter } from "@@/create-router";
+
+/** Mounted at `/api/finances`. The prefix comes from the manifest's `publisher`; nothing here sets it. */
+export const router = createRouter();
+
+router.get("/ping", (ctx) => ctx.json({ plugin: "finances", ok: true }));