fix(build): make oRPC/tRPC dist runnable under node ESM (deploy crashloop)

flake.nix only rewrote @/ aliases but left extensionless relative imports
(./router) in compiled dist/. node dist/index.js (how prod runs) cannot
resolve extensionless ESM specifiers -> ERR_MODULE_NOT_FOUND -> backend
crashlooped (444 restarts, port 4001 dead). Extract the fixer into a shared
scripts/fix-imports.mjs that appends .js to extensionless relative imports and
rewrites @/ aliases, and wire it into backend + discord-gateway build phases.

Verified: fresh tsc + fixer -> node dist/index.js boots; oRPC over /trpc
serves both HTTP POST and WebSocket (config/dashboard/voice/moderation/
media/chatbot/analysis) end-to-end against Postgres + Redis. next build
passes with the oRPC client + partysocket.

services/frontend/src/lib/orpc/client.ts

@@ -0,0 +1,36 @@
+"use client";
+
+import { createORPCClient } from "@orpc/client";
+import { RPCLink } from "@orpc/client/websocket";
+import PartySocket from "partysocket";
+import type { ORPCClient } from "./types";
+
+/**
+ * oRPC client over WebSocket (browser only).
+ *
+ * oRPC's own WebSocket RPCLink takes a caller-provided socket and does NOT
+ * auto-reconnect, so we back it with partysocket — a reconnecting WebSocket
+ * whose `host` + `basePath: "trpc"` resolves to exactly `/trpc`, matching the
+ * backend's oRPC WS mount. partysocket keeps a stable socket identity across
+ * reconnects, which is what oRPC's RPCLink expects.
+ *
+ * The client is loosely typed (see ./types): we do NOT import the backend
+ * router's type into the FE (fragile coupling). api/* wrappers assert leaf
+ * results to the frontend's local types.
+ */
+const orpc: ORPCClient = (() => {
+  if (typeof window === "undefined") {
+    // SSR fallback — api/* callers are client components, never run server-side.
+    return undefined as unknown as ORPCClient;
+  }
+
+  const socket = new PartySocket({
+    host: window.location.host,
+    basePath: "trpc",
+  });
+
+  const link = new RPCLink({ websocket: socket });
+  return createORPCClient(link) as unknown as ORPCClient;
+})();
+
+export { orpc };