Fix build: resolve Turbopack client bundle and font issues

- Move EXPENSE_CATEGORIES to ~/lib/expense-categories.ts to break
  server router import chain from client component
- Use inline import() types in trpc/react.tsx to prevent Turbopack
  from including server modules (pg, db) in the client bundle
- Replace next/font/google with system font stacks to fix build
  failures in environments without Google Fonts access

https://claude.ai/code/session_012sqEgNQpx676isepeoX4Mi

src/trpc/react.tsx

@@ -7,7 +7,6 @@ import { type inferRouterInputs, type inferRouterOutputs } from "@trpc/server";
 import { useState } from "react";
 import SuperJSON from "superjson";
 
-import { type AppRouter } from "~/server/api/root";
 import { createQueryClient } from "./query-client";
 
 let clientQueryClientSingleton: QueryClient | undefined = undefined;
@@ -22,21 +21,22 @@ const getQueryClient = () => {
   return clientQueryClientSingleton;
 };
 
-export const api = createTRPCReact<AppRouter>();
+// Use inline import() type to avoid pulling server modules into the client bundle
+export const api = createTRPCReact<import("~/server/api/root").AppRouter>();
 
 /**
  * Inference helper for inputs.
  *
  * @example type HelloInput = RouterInputs['example']['hello']
  */
-export type RouterInputs = inferRouterInputs<AppRouter>;
+export type RouterInputs = inferRouterInputs<import("~/server/api/root").AppRouter>;
 
 /**
  * Inference helper for outputs.
  *
  * @example type HelloOutput = RouterOutputs['example']['hello']
  */
-export type RouterOutputs = inferRouterOutputs<AppRouter>;
+export type RouterOutputs = inferRouterOutputs<import("~/server/api/root").AppRouter>;
 
 export function TRPCReactProvider(props: { children: React.ReactNode }) {
   const queryClient = getQueryClient();