feat: communication spine — gateway, TUI, Discord

Gateway:
- Agent service wrapping Pi SDK createAgentSession (in-process)
- Chat WebSocket gateway (Socket.IO) streaming agent events
- Chat REST controller for synchronous requests
- NestJS module structure: AgentModule (global), ChatModule

CLI:
- Ink-based TUI client connecting to gateway via WebSocket
- Commander-based CLI with `mosaic tui` command
- Streaming message display with React components

Discord:
- Discord.js bot with mention-based activation + DM support
- Routes messages through gateway WebSocket
- Chunked response delivery (2000-char Discord limit)
- Single-guild binding for v0.1.0

Architecture: All channels → Gateway WebSocket → Pi SDK → LLM

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/cli/package.json

@@ -1,10 +1,11 @@
 {
   "name": "@mosaic/cli",
   "version": "0.0.0",
+  "type": "module",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
   "bin": {
-    "mosaic": "dist/index.js"
+    "mosaic": "dist/cli.js"
   },
   "exports": {
     ".": {
@@ -14,11 +15,22 @@
   },
   "scripts": {
     "build": "tsc",
+    "dev": "tsx src/cli.ts",
     "lint": "eslint src",
     "typecheck": "tsc --noEmit",
     "test": "vitest run"
   },
+  "dependencies": {
+    "ink": "^5.0.0",
+    "ink-text-input": "^6.0.0",
+    "ink-spinner": "^5.0.0",
+    "react": "^18.3.0",
+    "socket.io-client": "^4.8.0",
+    "commander": "^13.0.0"
+  },
   "devDependencies": {
+    "@types/react": "^18.3.0",
+    "tsx": "^4.0.0",
     "typescript": "^5.8.0",
     "vitest": "^2.0.0"
   }