feat(audit): 审计修复第四轮 — 跨会话搜索、LLM压缩集成、Presentation渲染器

- S9: MessageSearch 新增 Session/Global 双模式，Global 调用 VikingStorage memory_search
- M4b: LLM 压缩器集成到 kernel AgentLoop，支持 use_llm 配置切换
- M4c: 压缩时自动提取记忆到 VikingStorage (runtime + tauri 双路径)
- H6: 新增 ChartRenderer(recharts)、Document/Slideshow 完整渲染
- 累计修复 23 项，整体完成度 ~72%，真实可用率 ~80%

desktop/package.json

@@ -45,7 +45,10 @@
     "lucide-react": "^0.577.0",
     "react": "^19.2.4",
     "react-dom": "^19.2.4",
+    "react-markdown": "^10.1.0",
     "react-window": "^2.2.7",
+    "recharts": "^3.8.1",
+    "remark-gfm": "^4.0.1",
     "smol-toml": "^1.6.1",
     "tailwind-merge": "^3.5.0",
     "tweetnacl": "^1.0.3",