feat(skill): refactor skill system with router + references structure (#192)

Refactors SKILL.md into a router + reference documentation system:
- Main SKILL.md now contains routing table and quick commands
- Detailed docs split into references/ (search, social, career, dev, web, video)
- CLI skill install copies entire directory including references/
- Resolves conflicts with recent merges (#210, #213)
- Fixes xreach→bird in quick commands

Original PR by @Citrus086, merged with conflict resolution.

Co-Authored-By: Citrus086 <Citrus086@users.noreply.github.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

agent_reach/skill/references/web.md

@@ -0,0 +1,77 @@
+# 网页阅读
+
+通用网页、微信公众号、RSS。
+
+## 通用网页 (Jina Reader)
+
+```bash
+# 读取任意网页内容
+curl -s "https://r.jina.ai/URL"
+
+# 示例
+curl -s "https://r.jina.ai/https://example.com/article"
+```
+
+**适用场景**: 大多数网页可以直接用 Jina Reader 读取。
+
+## Web Reader (MCP)
+
+```bash
+# 读取网页内容 (Markdown 格式)
+mcporter call 'web-reader.webReader(url: "https://example.com")'
+
+# 保留图片
+mcporter call 'web-reader.webReader(url: "https://example.com", retain_images: true)'
+
+# 纯文本格式
+mcporter call 'web-reader.webReader(url: "https://example.com", return_format: "text")'
+```
+
+**适用场景**: 需要更精确控制输出格式时使用。
+
+## 微信公众号 / WeChat Articles
+
+**注意**: 微信公众号文章无法用 Jina Reader 或 curl 直接读取，必须使用专用工具。
+
+### 搜索文章 (miku_ai)
+
+```python
+python3 -c "
+import asyncio
+from miku_ai import get_wexin_article
+async def s():
+    for a in await get_wexin_article('query', 5):
+        print(f'{a[\"title\"]} | {a[\"url\"]}')
+asyncio.run(s())
+"
+```
+
+### 读取文章 (Camoufox - 绕过微信反爬)
+
+```bash
+cd ~/.agent-reach/tools/wechat-article-for-ai && python3 main.py "https://mp.weixin.qq.com/s/ARTICLE_ID"
+```
+
+> **重要**: 微信文章必须用 Camoufox 读取，其他方法会失败。
+
+## RSS (feedparser)
+
+```python
+python3 -c "
+import feedparser
+for e in feedparser.parse('FEED_URL').entries[:5]:
+    print(f'{e.title} — {e.link}')
+"
+```
+
+**适用场景**: 订阅博客、新闻源、播客等 RSS feed。
+
+## 选择指南
+
+| 场景 | 推荐工具 |
+|-----|---------|
+| 通用网页 | Jina Reader (`curl r.jina.ai`) |
+| 需要图片/格式控制 | web-reader MCP |
+| 微信公众号 | Camoufox (读取) + miku_ai (搜索) |
+| RSS 订阅 | feedparser |
+| 微博/知乎等 | Jina Reader |