feat(scripts): add unified startup scripts for full stack development

Add comprehensive startup scripts for managing all ZCLAW services:

Windows (PowerShell):
- start.ps1 / start-all.ps1 - Unified service launcher
- Supports -NoBrowser, -NoGateway, -Dev, -Stop flags

Unix (Bash):
- start.sh - Cross-platform launcher for macOS/Linux

Makefile:
- make start / make start-unix
- make desktop / make desktop-build
- make setup / make test / make clean

pnpm commands:
- pnpm start - Start all services
- pnpm start:dev - Development mode with hot reload
- pnpm start:no-browser - Skip ChromeDriver
- pnpm start:no-gateway - Skip OpenFang gateway
- pnpm desktop - Start Tauri only
- pnpm chromedriver - Start ChromeDriver only

Services managed:
1. ChromeDriver (port 4444) - Browser automation
2. OpenFang Gateway (port 4200) - AI Agent runtime
3. Tauri Desktop - React + Rust frontend

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

package.json

@@ -10,7 +10,15 @@
     "test": "vitest run",
     "gateway:start": "openfang gateway start",
     "gateway:status": "openfang gateway status",
-    "gateway:doctor": "openfang doctor"
+    "gateway:doctor": "openfang doctor",
+    "start": "pwsh -File ./start-all.ps1",
+    "start:dev": "pwsh -File ./start-all.ps1 -Dev",
+    "start:no-browser": "pwsh -File ./start-all.ps1 -NoBrowser",
+    "start:no-gateway": "pwsh -File ./start-all.ps1 -NoGateway",
+    "start:stop": "pwsh -File ./start-all.ps1 -Stop",
+    "desktop": "cd desktop && pnpm tauri dev",
+    "desktop:build": "cd desktop && pnpm tauri build",
+    "chromedriver": "chromedriver --port=4444"
   },
   "keywords": [
     "ai",