feat(rpc): scaffold the package and shared contract types

tsconfig.json

@@ -75,6 +75,7 @@
       "@wrnexus/ui/component-reference.json": ["./packages/ui/component-reference.json"],
       "@wrnexus/ui/ui.css": ["./packages/ui/ui.css"],
       "@wrnexus/validation": ["./packages/validation/src/index.ts"],
+      "@wrnexus/rpc": ["./packages/rpc/src/index.ts"],
       "@wrnexus/ai/*": ["./packages/ai/src/*.ts"],
       "@wrnexus/authz/*": ["./packages/authz/src/*.ts"],
       "@wrnexus/cli/*": ["./packages/cli/src/*.ts"],