feat: add npm global package for one-command install

Add a Node.js CLI wrapper that allows installing AutoForge globally via
`npm install -g autoforge-ai` and running it with a single `autoforge`
command. The CLI handles Python detection, venv management, config
loading, and uvicorn server lifecycle automatically.

New files:
- package.json: npm package config with bin entry, files whitelist,
  and prepublishOnly script that builds the UI
- bin/autoforge.js: thin entry point that imports lib/cli.js
- lib/cli.js: main CLI module (~790 lines) with cross-platform Python
  3.11+ detection, composite venv marker for smart invalidation
  (requirements hash + Python version + path), .env config management
  at ~/.autoforge/.env, server startup with PID file and port detection,
  and signal handling with process tree cleanup
- requirements-prod.txt: runtime-only deps (excludes ruff, mypy, pytest)
- .npmignore: excludes dev files, tests, __pycache__, UI source

Modified files:
- ui/package.json: rename to autoforge-ui to avoid confusion with root
- .gitignore: add *.tgz for npm pack output
- README.md: add npm install as primary quick start method, document
  CLI commands, add Ollama/Vertex AI config sections, new troubleshooting
  entries for Python/venv issues
- GettingStarted.tsx: add Installation, Quick Start, and CLI Commands
  sections to in-app documentation with command reference table
- docsData.ts: add installation and cli-commands sidebar entries

Published as autoforge-ai@0.1.0 on npm.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.npmignore

@@ -0,0 +1,32 @@
+venv/
+**/__pycache__/
+**/*.pyc
+.git/
+.github/
+node_modules/
+test_*.py
+tests/
+generations/
+*.db
+.env
+requirements.txt
+CLAUDE.md
+LICENSE.md
+README.md
+ui/src/
+ui/node_modules/
+ui/tsconfig*.json
+ui/vite.config.ts
+ui/eslint.config.js
+ui/index.html
+ui/public/
+ui/playwright.config.ts
+ui/tests/
+start.bat
+start_ui.bat
+start.sh
+start_ui.sh
+start_ui.py
+.claude/agents/
+.claude/skills/
+.claude/settings.json