feat(qveris): add QVeris MCP plugin

[FairyZhang-sunny]

What / 改动内容

Adds the official QVeris integration to the ZCode public plugin marketplace.

新增 QVeris 官方集成至 ZCode 公开插件广场。

• Adds a plugin-bundled stdio MCP server using the official @qverisai/mcp@0.14.0 package.
• Adds a focused QVeris skill for the discover → inspect → probe → call workflow, including billing and external-side-effect safeguards.
• Adds equivalent English and Chinese setup, security, troubleshooting, data handling, and license documentation.
• Registers qveris 0.1.0 in the utilities marketplace category.

User-visible behavior / 用户可见行为

After installing the plugin and making QVERIS_API_KEY available to the ZCode desktop process, users get a plugin-bundled QVeris MCP server plus Agent guidance for discovering and invoking external APIs and live data capabilities.

安装插件并让 ZCode 桌面进程读取 QVERIS_API_KEY 后，用户可使用插件内置的 QVeris MCP 服务，并由 Skill 引导 Agent 发现和调用外部 API 与实时数据能力。

Dependencies, network access, and side effects / 依赖、网络与副作用

• Requires Node.js 18.2+, npx, a QVeris account, and QVERIS_API_KEY supplied through the process environment.
• First startup downloads and executes the exact npm package @qverisai/mcp@0.14.0.
• The MCP server connects to QVeris over HTTPS; selected third-party providers may receive capability parameters.
• Some call operations consume QVeris credits or cause provider-side state changes. The bundled skill requires confirmation when the current user request has not already authorized the material effect.
• The plugin ships no Hooks and writes no files itself. The upstream MCP export mode may write JSONL under .qveris/exports/ only when explicitly requested.
• Marketplace content is Apache-2.0; the upstream QVeris MCP package is MIT licensed.

Verification / 验证

• python3 scripts/validate.py — passed (17 plugin(s) validated)
• python3 scripts/build_dist.py — passed (17 plugin artifact(s), QVeris artifact built)
• git diff --check — passed
• Offline stdio smoke test against the cached, exact @qverisai/mcp@0.14.0 package — initialize and tools/list passed; 9 tools exposed; dummy key only and no external call

Full installation through the ZCode plugin UI has not yet been exercised from this checkout. The existing QVeris hosted MCP endpoint was independently confirmed to initialize successfully, but this PR's install path should still receive one marketplace-install smoke test during review.

Self-check / 自查清单

• Plugin name is unique kebab-case; directory is plugins/qveris
• version is 0.1.0 in BOTH plugin.json and marketplace.json
• README.md (EN) and README_CN.md (中文) are equivalent
• description_i18n has both en and zh-CN
• No secrets, machine-specific paths, or private dependencies
• Model/API/network dependencies documented
• python3 scripts/validate.py and python3 scripts/build_dist.py pass locally