feat(cli): scaffold @claudemesh/cli MCP client package (stubs)

The user-facing tool. Two invocation modes:
  - `claudemesh mcp`           → MCP server (stdio), consumed by Claude Code
  - `claudemesh <subcommand>`  → human CLI

Layout:
  apps/cli/
  ├── package.json       bin: { claudemesh: ./src/index.ts }
  ├── README.md          install + usage
  └── src/
      ├── index.ts       dispatcher (mcp | install | join | list | leave | --help)
      ├── env.ts         CLAUDEMESH_BROKER_URL, CONFIG_DIR, DEBUG
      ├── mcp/
      │   ├── server.ts  MCP stdio server with 5 tools
      │   ├── tools.ts   tool schemas (send_message, list_peers,
      │   │              check_messages, set_summary, set_status)
      │   └── types.ts
      ├── ws/client.ts   broker connection (stub for 15b)
      ├── state/config.ts ~/.claudemesh/config.json (joined meshes + keys)
      └── commands/
          ├── install.ts print `claude mcp add ...` instruction
          ├── join.ts    parse ic://join/... (stub, Step 17)
          ├── list.ts    show joined meshes
          └── leave.ts   remove mesh from local config

Tool stubs return "not connected, run `claudemesh join <invite-link>`"
errors until 15b wires the WS client.

Verified:
- `bun src/index.ts --help` → prints usage
- `bun src/index.ts install` → prints MCP add command with resolved path
- `bun src/index.ts list` → "No meshes joined yet"
- `bun src/index.ts mcp` (via stdin) → returns tools/list with all 5 tools

Deps: @modelcontextprotocol/sdk, ws, libsodium-wrappers, zod.
Lockfile regenerated in the same commit per claudemesh-3's flag —
avoids breaking Coolify's --frozen-lockfile deploys.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/cli/src/env.ts

@@ -0,0 +1,27 @@
+import { z } from "zod";
+
+/**
+ * CLI environment config.
+ *
+ * Read once at startup. Overridable via env vars so users can point
+ * at a self-hosted broker or a staging instance without rebuilding.
+ */
+const envSchema = z.object({
+  CLAUDEMESH_BROKER_URL: z.string().default("wss://ic.claudemesh.com/ws"),
+  CLAUDEMESH_CONFIG_DIR: z.string().optional(),
+  CLAUDEMESH_DEBUG: z.coerce.boolean().default(false),
+});
+
+export type CliEnv = z.infer<typeof envSchema>;
+
+export function loadEnv(): CliEnv {
+  const parsed = envSchema.safeParse(process.env);
+  if (!parsed.success) {
+    console.error("[claudemesh] invalid environment:");
+    console.error(z.treeifyError(parsed.error));
+    process.exit(1);
+  }
+  return parsed.data;
+}
+
+export const env = loadEnv();