feat(harness): 用戶 CC harness（acr install-harness）+ 公開 repo 只留對外

讓「用 arcrun 開發」的用戶，他的 CC 自動載入 arcrun 防護、不退回自寫 Python。

新增 user-cc-harness（SDD: .agents/specs/user-cc-harness，本機）：
- acr install-harness：冪等裝進用戶當前專案（新/舊專案皆可），acr init 末尾也順便裝
  - CLAUDE.md arcrun 區塊（標記包夾，append 不破壞既有）
  - .claude/skills/arcrun-mindset（世界觀 + 資源去哪取 acr parts/auth-recipe）
  - .claude/commands/arcrun.md（/arcrun slash command）
  - .claude/hooks/arcrun-guard.sh（python→提醒不硬擋、暴露→exit 2、每條含正路）
  - settings.json 合併 hook（不覆蓋用戶既有 hooks/設定）
- llms.txt + README「給 AI」段：第一接觸點（用戶丟連結，CC 讀了知道第一步 install-harness）
  含 CF 憑證白話照抄式引導（不對用戶講 KV/Worker/R2 術語）
- harness 素材內嵌 npm 套件（cli/harness/，files 帶上），不依賴用戶有 arcrun repo
- 實測：空目錄/冪等/既有檔合併皆通過，tsc exit 0，npm pack 含 harness 5 檔

公開 repo 清理（richblack：用戶要用不要開發 arcrun）：
- git rm --cached 移除開發痕跡 + 思考過程出公開 repo（本機保留供 richblack 開發）：
  .claude/CLAUDE.md/AGENTS.md/.agents/docs/DECISIONS/BACKLOG/landing/.github
- .gitignore 防回流；補 MIT LICENSE

MCP（P7）納入 install-harness/update 的接點已設計，實作待 MCP 對齊（BACKLOG 另一條線）。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

landing/app/api-docs/page.tsx

@@ -1,100 +0,0 @@
-'use client';
-
-import { useEffect, useRef } from 'react';
-import Link from 'next/link';
-import SiteNav from '../components/SiteNav';
-
-const API_BASE = process.env.NEXT_PUBLIC_API_BASE ?? 'https://cypher.arcrun.dev';
-
-export default function ApiDocsPage() {
-  const containerRef = useRef<HTMLDivElement>(null);
-  const initialized = useRef(false);
-
-  useEffect(() => {
-    if (initialized.current || !containerRef.current) return;
-    initialized.current = true;
-
-    // Dynamically load Swagger UI from CDN
-    const link = document.createElement('link');
-    link.rel = 'stylesheet';
-    link.href = 'https://unpkg.com/swagger-ui-dist@5/swagger-ui.css';
-    document.head.appendChild(link);
-
-    const script = document.createElement('script');
-    script.src = 'https://unpkg.com/swagger-ui-dist@5/swagger-ui-bundle.js';
-    script.onload = () => {
-      const SwaggerUIBundle = (window as unknown as { SwaggerUIBundle: (opts: unknown) => void }).SwaggerUIBundle;
-      if (!SwaggerUIBundle || !containerRef.current) return;
-      SwaggerUIBundle({
-        url: `${API_BASE}/openapi.json`,
-        dom_id: '#swagger-ui',
-        presets: [(window as unknown as { SwaggerUIBundle: { presets: { apis: unknown } } }).SwaggerUIBundle.presets.apis],
-        layout: 'BaseLayout',
-        defaultModelsExpandDepth: -1,
-        docExpansion: 'list',
-        filter: true,
-        tryItOutEnabled: true,
-        supportedSubmitMethods: ['get', 'post', 'put', 'delete', 'patch'],
-        requestInterceptor: (request: { headers: Record<string, string> }) => {
-          // Inject API key from localStorage if present
-          const key = localStorage.getItem('arcrun_api_key');
-          if (key) request.headers['X-Arcrun-API-Key'] = key;
-          return request;
-        },
-      });
-    };
-    document.head.appendChild(script);
-
-    return () => {
-      // cleanup not strictly needed for page navigation
-    };
-  }, []);
-
-  return (
-    <div className="min-h-screen bg-[#0a0a0a] text-[#ededed]">
-      <SiteNav currentPath="/api-docs" />
-
-      {/* Header */}
-      <div className="max-w-5xl mx-auto px-6 py-8">
-        <h1 className="text-2xl font-bold text-white mb-2">API Reference</h1>
-        <p className="text-[#555] text-sm mb-2">
-          這是 arcrun 的原始 API。Python / JS lib 是它的包裝，任何能發 HTTP request 的工具都能直接用。
-        </p>
-        <p className="text-[#444] text-xs mb-6">
-          Endpoint: <span className="font-mono text-[#666]">{API_BASE}</span>
-        </p>
-
-        {/* API Key hint */}
-        <div className="bg-[#111] border border-[#222] rounded-lg p-4 mb-8 text-sm">
-          <p className="text-[#666] mb-2">
-            若要在此頁面試打 API，請先設定 API Key：
-          </p>
-          <ApiKeyInput />
-        </div>
-
-        {/* Swagger UI */}
-        <div className="bg-white rounded-xl overflow-hidden" ref={containerRef}>
-          <div id="swagger-ui" className="min-h-96"></div>
-        </div>
-      </div>
-    </div>
-  );
-}
-
-function ApiKeyInput() {
-  return (
-    <div className="flex gap-2">
-      <input
-        type="text"
-        placeholder="ak_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-        className="flex-1 bg-[#0a0a0a] border border-[#2a2a2a] rounded px-3 py-1.5 text-xs font-mono text-[#cdd6f4] focus:outline-none focus:border-indigo-700"
-        onChange={(e) => {
-          if (e.target.value.startsWith('ak_')) {
-            localStorage.setItem('arcrun_api_key', e.target.value);
-          }
-        }}
-      />
-      <span className="text-[#444] text-xs self-center">自動注入到 requests</span>
-    </div>
-  );
-}