feat(core-trpc): scaffold tRPC client with React Query providers

- createTRPCContext + useTRPC hook for typed client access
- NextTrpcProvider with SSR-safe absolute URL resolution
- TanstackTrpcProvider for TanStack Start apps
- /api/trpc catch-all route handler in web-next
- Wire NextTrpcProvider into app providers
- Add @repo/core-trpc to transpilePackages

packages/core-trpc/vitest.config.ts

@@ -0,0 +1,7 @@
+import path from "node:path";
+import { mergeConfig } from "vitest/config";
+import { jsdomVitestConfig } from "@repo/core-typescript/vitest.base.jsdom";
+
+export default mergeConfig(jsdomVitestConfig, {
+  resolve: { alias: { "@": path.resolve(__dirname, "./src") } },
+});