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>

ui/package-lock.json

@@ -1,11 +1,11 @@
 {
-  "name": "autoforge",
+  "name": "autoforge-ui",
   "version": "1.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "autoforge",
+      "name": "autoforge-ui",
       "version": "1.0.0",
       "dependencies": {
         "@radix-ui/react-checkbox": "^1.3.3",
@@ -50,6 +50,18 @@
         "vite": "^7.3.0"
       }
     },
+    "..": {
+      "name": "autoforge-ai",
+      "version": "0.1.0",
+      "extraneous": true,
+      "license": "AGPL-3.0",
+      "bin": {
+        "autoforge": "bin/autoforge.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
     "node_modules/@babel/code-frame": {
       "version": "7.27.1",
       "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.27.1.tgz",