feat(skills): 新增 watchless 与 impeccable 两个 external skill (#60)

## 背景

新增两个社区 skill 的 marketplace 指针条目，两者此前均不在 market 中。

## 改动

新增 2 个 external entry（`entry.json`，git 指针型，含 `zh-CN` / `en-US` i18n）：

| skill | category | license | source | 简介 |
|---|---|---|---|---|
| watchless | media | MIT |
[chenzixin1/watchless](https://github.com/chenzixin1/watchless) |
将视频转成以关键帧截图为主线的完整视觉文档，输出 HTML/PDF/ZIP |
| impeccable | design | Apache-2.0 |
[pbakaus/impeccable](https://github.com/pbakaus/impeccable) | 让 AI
更懂前端设计的设计语言，覆盖 UX/可访问性/排版/配色/动效/设计系统 |

同步更新：
- `README.md`：external `20 → 22`、total `50 → 52`，外部条目列表按字母序插入
`impeccable`、`watchless`
- `manifest.json`：`stats.totalSkills` `50 → 52`

## 规则遵循

- entry.json 字段对齐现有 git 型指针（如 mattpocock-skills），格式一致
- category 使用 `categories.json` 已声明的合法 slug（media / design）
- `source.ref` 固定到当前最新 commit，保证可复现
- 两个上游仓库均为标准 skill（含 SKILL.md / skill 定义），许可允许再分发

## 验证

- 本地运行 `scripts/i18n/validate-i18n.py`：`OK: no i18n issues found.`（退出码
0）
- entry.json 均为合法 JSON，i18n 完整

README.md

@@ -24,8 +24,8 @@ The market currently contains:
 
 - `1` Agent: `desirecore`
 - `30` local built-in skills with `SKILL.md`
-- `20` external skill entries with `entry.json`
+- `22` external skill entries with `entry.json`
-- `50` publishable skills in total (`SKILL.md` + `entry.json`)
+- `52` publishable skills in total (`SKILL.md` + `entry.json`)
 
 ## Skill Sources
 
@@ -45,9 +45,10 @@ External entries are marketplace pointers to Git/Web/ZIP sources:
 
 ```text
 agent-reach, ai-news-radar, amap-jsapi-skill, dingtalk-api, flyai-skill,
-follow-builders, ian-xiaohei-illustrations, khazix-skills, larksuite-cli,
+follow-builders, ian-xiaohei-illustrations, impeccable, khazix-skills,
-luckin-my-coffee, mattpocock-skills, minimax-image-gen, minimax-tts,
+larksuite-cli, luckin-my-coffee, mattpocock-skills, minimax-image-gen,
-mt-paotui-for-client, netease-skills, taste-skill, wechatpay-skills, wecom-cli
+minimax-tts, mt-paotui-for-client, netease-skills, taste-skill, watchless,
+wechatpay-skills, wecom-cli
 ```
 
 ## Data Formats

manifest.json

@@ -27,7 +27,7 @@
   },
   "stats": {
     "totalAgents": 1,
-    "totalSkills": 50,
+    "totalSkills": 52,
     "lastUpdated": "2026-07-19"
   },
   "features": [

skills/impeccable/entry.json

@@ -0,0 +1,37 @@
+{
+  "id": "impeccable",
+  "name": "Impeccable",
+  "category": "design",
+  "icon": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"24\" height=\"24\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M12 3 4 7v5c0 4.5 3.2 7.9 8 9 4.8-1.1 8-4.5 8-9V7l-8-4Z\" stroke=\"#2563EB\" stroke-width=\"1.7\" stroke-linejoin=\"round\"/><path d=\"m9 12 2 2 4-4\" stroke=\"#2563EB\" stroke-width=\"1.7\" stroke-linecap=\"round\" stroke-linejoin=\"round\"/></svg>",
+  "tags": [
+    "design",
+    "frontend",
+    "ui",
+    "pbakaus"
+  ],
+  "i18n": {
+    "zh-CN": {
+      "name": "Impeccable",
+      "shortDesc": "让 AI 更懂设计的前端设计语言：覆盖 UX 审查、视觉层级、可访问性、排版、配色、动效与可复用设计系统，把界面打磨到生产级"
+    },
+    "en-US": {
+      "name": "Impeccable",
+      "shortDesc": "A design language that makes AI better at frontend: UX review, visual hierarchy, accessibility, typography, color, motion and reusable design systems"
+    }
+  },
+  "maintainer": {
+    "name": "Paul Bakaus",
+    "verified": false,
+    "account": "pbakaus",
+    "url": "https://github.com/pbakaus/impeccable"
+  },
+  "stewardship": "community",
+  "license": "Apache-2.0",
+  "redistribution": "allowed",
+  "source": {
+    "kind": "git",
+    "repoUrl": "https://github.com/pbakaus/impeccable.git",
+    "repoBranch": "main",
+    "ref": "e4ab5e24bdf5321b72163d2fbcbe6fa985c848ba"
+  }
+}

skills/watchless/entry.json

@@ -0,0 +1,37 @@
+{
+  "id": "watchless",
+  "name": "Watchless",
+  "category": "media",
+  "icon": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"24\" height=\"24\" viewBox=\"0 0 24 24\" fill=\"none\"><rect x=\"3\" y=\"5\" width=\"18\" height=\"14\" rx=\"2\" stroke=\"#2563EB\" stroke-width=\"1.7\"/><path d=\"m10 9 5 3-5 3V9Z\" fill=\"#2563EB\"/><path d=\"M3 17h18\" stroke=\"#2563EB\" stroke-width=\"1.7\" stroke-linecap=\"round\"/></svg>",
+  "tags": [
+    "video",
+    "transcript",
+    "notes",
+    "chenzixin1"
+  ],
+  "i18n": {
+    "zh-CN": {
+      "name": "Watchless",
+      "shortDesc": "把视频转成以关键帧截图为主线的完整视觉文档：转写为事实来源、截图保留画面证据，输出 HTML/PDF/ZIP，读者无需再看原视频"
+    },
+    "en-US": {
+      "name": "Watchless",
+      "shortDesc": "Turns a video into a complete keyframe-led visual document with faithful transcript-based notes, exported as HTML, PDF or a shareable ZIP"
+    }
+  },
+  "maintainer": {
+    "name": "chenzixin1",
+    "verified": false,
+    "account": "chenzixin1",
+    "url": "https://github.com/chenzixin1/watchless"
+  },
+  "stewardship": "community",
+  "license": "MIT",
+  "redistribution": "allowed",
+  "source": {
+    "kind": "git",
+    "repoUrl": "https://github.com/chenzixin1/watchless.git",
+    "repoBranch": "main",
+    "ref": "a09c0edc6c3121c05e9824ef556256441d291d4f"
+  }
+}