init: personal markdown knowledge base server

- Auto-discovers .md files from configurable content roots
- On-the-fly markdown → HTML rendering (marked + highlight.js)
- Directory tree navigation sidebar
- Full-text search across all documents
- Dark mode, responsive design, Ctrl+K quick search
- Frontmatter (YAML) support via gray-matter
- Configurable via config.json

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

config.json

@@ -0,0 +1,10 @@
+{
+  "title": "我的知识库",
+  "port": 5173,
+  "host": "0.0.0.0",
+  "contentRoots": [
+    { "label": "DPDK → DPU 学习", "path": "../packet_forge/dpdk_study" }
+  ],
+  "excludeDirs": ["node_modules", ".git", ".claude", "source", "assets", "build", "dist"],
+  "excludeFiles": [".gitkeep", "package-lock.json"]
+}