feat(01.1-06): add tRPC HTTP adapter and CLI client

- Create src/server/trpc-adapter.ts with fetch adapter for node:http
- Create src/cli/trpc-client.ts with typed client factory functions
- Update CoordinationServer to route /trpc/* to tRPC handler
- Move @trpc/client from devDeps to regular deps
- Keep /health and /status HTTP endpoints for backwards compatibility

src/cli/trpc-client.ts

@@ -0,0 +1,54 @@
+/**
+ * tRPC Client for CLI
+ *
+ * Type-safe client for communicating with the coordination server.
+ * Uses httpBatchLink for efficient request batching.
+ */
+
+import { createTRPCClient, httpBatchLink } from '@trpc/client';
+import type { AppRouter } from '../trpc/index.js';
+
+/** Default server port */
+const DEFAULT_PORT = 3847;
+
+/** Default server host */
+const DEFAULT_HOST = '127.0.0.1';
+
+/**
+ * Type-safe tRPC client for the coordination server.
+ */
+export type TrpcClient = ReturnType<typeof createTRPCClient<AppRouter>>;
+
+/**
+ * Creates a tRPC client for the coordination server.
+ *
+ * @param port - Server port (default: 3847)
+ * @param host - Server host (default: 127.0.0.1)
+ * @returns Type-safe tRPC client
+ */
+export function createTrpcClient(
+  port: number = DEFAULT_PORT,
+  host: string = DEFAULT_HOST
+): TrpcClient {
+  return createTRPCClient<AppRouter>({
+    links: [
+      httpBatchLink({
+        url: `http://${host}:${port}/trpc`,
+      }),
+    ],
+  });
+}
+
+/**
+ * Creates a tRPC client using environment variables or defaults.
+ *
+ * Uses CW_PORT and CW_HOST environment variables if available,
+ * falling back to defaults (127.0.0.1:3847).
+ *
+ * @returns Type-safe tRPC client
+ */
+export function createDefaultTrpcClient(): TrpcClient {
+  const port = process.env.CW_PORT ? parseInt(process.env.CW_PORT, 10) : DEFAULT_PORT;
+  const host = process.env.CW_HOST ?? DEFAULT_HOST;
+  return createTrpcClient(port, host);
+}