feat: add guizang-ppt market skill (vendored from op7418, AGPL-3.0) (#20)

## 概述 / Summary

新增市场技能 **`guizang-ppt`**（归藏网页 PPT），vendored 自上游开源项目
[op7418/guizang-ppt-skill](https://github.com/op7418/guizang-ppt-skill)。

Add a new **market skill** `guizang-ppt` — generates single-file HTML
horizontal-swipe slide decks (web PPT) in two visual systems (editorial
"magazine × e-ink" / "Swiss International"). Vendored from the upstream
open-source project.

## 变更内容 / Changes

- `skills/guizang-ppt/`：SKILL.md（DesireCore frontmatter 覆盖层 +
上游正文）、`references/`（10）、`assets/`（2 模板 + motion.min.js + 9 张
webp）、`scripts/validate-swiss-deck.mjs`、`LICENSE`（AGPL-3.0）、`NOTICE.md`（署名与合规）
- `skills/guizang-ppt/_desirecore/`：DesireCore 维护态（不随上游覆盖）
- `frontmatter.yaml`：市场 frontmatter 覆盖层（i18n: zh-CN 源 + en-US 显示串，body
暂回退中文，留给 CI 翻译）
  - `upstream.json`：上游溯源（commit `014c572`、AGPL-3.0、作者 歸藏/op7418）
- `scripts/vendor/guizang-ppt.mjs`：可复用的 vendor 更新脚本（`--src <本地路径>` 或
`--ref <tag>`）
- `manifest.json`：`version` → `1.2.3`，`stats.totalSkills` → 25

## 定位 / Positioning

- **仅市场可选安装**：未加入 `builtin-skills.json`，不随客户端开机自动安装；用户在市场按需安装。
- 分类 `creative`；与已有 `pptx`（生成 .pptx 文件）区分：本技能生成 **HTML deck**。

## 许可与署名 / License & Attribution

上游为 **AGPL-3.0**。本技能保留原 `LICENSE` 与作者署名（`NOTICE.md` + `metadata.author`
+ `market.maintainer`），作为聚合内容分发。

## 校验 / Validation

- `python3 scripts/i18n/validate-i18n.py skills/guizang-ppt` → `OK: no
i18n issues found.`

## 手动更新流程 / Manual update

上游发版时：`node scripts/vendor/guizang-ppt.mjs --ref <tag>` → 核对 diff → 必要时
bump `_desirecore/frontmatter.yaml#version` 与 `manifest.json` → 提交。

---
🤖 Generated with [Claude Code](https://claude.com/claude-code)

scripts/vendor/guizang-ppt.mjs

@@ -0,0 +1,146 @@
+#!/usr/bin/env node
+/**
+ * Vendor 更新器：把上游 op7418/guizang-ppt-skill 同步进官方市场的 skills/guizang-ppt/。
+ *
+ * 设计目标（“手动可更新”）：
+ *   - 上游内容（references/ assets/ scripts/ LICENSE + SKILL.md 正文）是“被 vendored”的，可重复覆盖；
+ *   - DesireCore 自己维护的元数据放在 skills/guizang-ppt/_desirecore/（frontmatter.yaml 覆盖层 + NOTICE.md），
+ *     vendor 时不被上游覆盖；
+ *   - 每次同步把上游 commit/版本写进 _desirecore/upstream.json，保证可追溯。
+ *
+ * 用法：
+ *   node scripts/vendor/guizang-ppt.mjs --src /path/to/local/guizang-ppt-skill   # 复用本地 clone
+ *   node scripts/vendor/guizang-ppt.mjs --ref v1.2.0                             # 联网 clone 指定 ref
+ *   node scripts/vendor/guizang-ppt.mjs                                          # 联网 clone 默认分支
+ *
+ * 同步后仍需人工：核对 diff、必要时 bump _desirecore/frontmatter.yaml#version 与 metadata.updated_at、
+ * 更新根 manifest.json，再 commit / push。
+ */
+
+import { execSync } from 'node:child_process'
+import {
+  existsSync,
+  readFileSync,
+  writeFileSync,
+  rmSync,
+  cpSync,
+  mkdtempSync,
+} from 'node:fs'
+import { join, dirname, resolve } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { tmpdir } from 'node:os'
+
+const SKILL_ID = 'guizang-ppt'
+const UPSTREAM_URL = 'https://github.com/op7418/guizang-ppt-skill.git'
+const DEFAULT_BRANCH = 'main'
+// 从上游仓库 vendor 进来的顶层条目（会被每次同步覆盖刷新）
+const VENDORED_ENTRIES = ['references', 'assets', 'scripts', 'LICENSE']
+
+const __dir = dirname(fileURLToPath(import.meta.url))
+const REPO_ROOT = resolve(__dir, '..', '..') // scripts/vendor -> 仓库根
+const SKILL_DIR = join(REPO_ROOT, 'skills', SKILL_ID)
+const DESIRE_DIR = join(SKILL_DIR, '_desirecore')
+const FRONTMATTER_FILE = join(DESIRE_DIR, 'frontmatter.yaml')
+
+function parseArgs(argv) {
+  const out = { src: null, ref: DEFAULT_BRANCH }
+  for (let i = 0; i < argv.length; i++) {
+    if (argv[i] === '--src') out.src = argv[++i]
+    else if (argv[i] === '--ref') out.ref = argv[++i]
+  }
+  return out
+}
+
+function git(cmd, cwd) {
+  return execSync(`git ${cmd}`, { cwd, encoding: 'utf-8', stdio: ['pipe', 'pipe', 'pipe'] }).trim()
+}
+
+/** 取得上游源目录与 commit/ref；本地 --src 优先，否则浅克隆。返回 { srcDir, commit, ref, cleanup } */
+function resolveSource(args) {
+  if (args.src) {
+    const srcDir = resolve(args.src)
+    if (!existsSync(join(srcDir, 'SKILL.md'))) {
+      throw new Error(`--src 指向的目录缺少 SKILL.md：${srcDir}`)
+    }
+    let commit = 'unknown'
+    try {
+      commit = git('rev-parse HEAD', srcDir)
+    } catch {
+      /* 非 git 目录则忽略 */
+    }
+    return { srcDir, commit, ref: args.ref, cleanup: () => {} }
+  }
+  const tmp = mkdtempSync(join(tmpdir(), 'guizang-vendor-'))
+  console.log(`→ 克隆上游 ${UPSTREAM_URL} (ref=${args.ref}) ...`)
+  execSync(`git clone --depth 1 --branch ${args.ref} ${UPSTREAM_URL} ${tmp}`, {
+    stdio: ['pipe', 'pipe', 'pipe'],
+  })
+  const commit = git('rev-parse HEAD', tmp)
+  return { srcDir: tmp, commit, ref: args.ref, cleanup: () => rmSync(tmp, { recursive: true, force: true }) }
+}
+
+/** 去掉上游 SKILL.md 的 frontmatter，返回正文 */
+function stripFrontmatter(text) {
+  const lines = text.split('\n')
+  if (lines[0].trim() !== '---') return text.trim() + '\n'
+  for (let i = 1; i < lines.length; i++) {
+    if (lines[i].trim() === '---') {
+      return lines.slice(i + 1).join('\n').replace(/^\n+/, '')
+    }
+  }
+  return text.trim() + '\n'
+}
+
+function main() {
+  const args = parseArgs(process.argv.slice(2))
+
+  if (!existsSync(FRONTMATTER_FILE)) {
+    throw new Error(`缺少覆盖层 frontmatter：${FRONTMATTER_FILE}`)
+  }
+  const frontmatter = readFileSync(FRONTMATTER_FILE, 'utf-8').trimEnd()
+
+  const { srcDir, commit, ref, cleanup } = resolveSource(args)
+  try {
+    // 1. 清理旧的 vendored 内容（保留 _desirecore/ 与 NOTICE.md 等维护态）
+    for (const entry of [...VENDORED_ENTRIES, 'SKILL.md']) {
+      rmSync(join(SKILL_DIR, entry), { recursive: true, force: true })
+    }
+
+    // 2. 复制上游 vendored 条目
+    for (const entry of VENDORED_ENTRIES) {
+      const from = join(srcDir, entry)
+      if (existsSync(from)) {
+        cpSync(from, join(SKILL_DIR, entry), { recursive: true })
+      } else {
+        console.warn(`  ⚠ 上游缺少 ${entry}，跳过`)
+      }
+    }
+
+    // 3. 生成 SKILL.md = 覆盖层 frontmatter + 上游正文
+    const upstreamSkill = readFileSync(join(srcDir, 'SKILL.md'), 'utf-8')
+    const body = stripFrontmatter(upstreamSkill)
+    writeFileSync(join(SKILL_DIR, 'SKILL.md'), `${frontmatter}\n\n${body}`)
+
+    // 4. 写溯源信息
+    const upstream = {
+      skillId: SKILL_ID,
+      repoUrl: UPSTREAM_URL,
+      branch: DEFAULT_BRANCH,
+      ref,
+      commit,
+      license: 'AGPL-3.0',
+      author: '歸藏 (op7418)',
+      vendoredAt: new Date().toISOString(),
+    }
+    writeFileSync(join(DESIRE_DIR, 'upstream.json'), `${JSON.stringify(upstream, null, 2)}\n`)
+
+    console.log('✓ vendor 完成')
+    console.log(`  upstream commit: ${commit}`)
+    console.log(`  skill dir:       skills/${SKILL_ID}/`)
+    console.log('  后续：核对 diff → 必要时 bump _desirecore/frontmatter.yaml#version 与根 manifest.json → commit')
+  } finally {
+    cleanup()
+  }
+}
+
+main()