chore(v2): 从兴邦预审v2白名单抽取独立可运行基座

按 docs/v2/05-implementation-plan.md §1 候选迁移表与 claude_use/T00 白名单，
从 55e2cdb 抽取 224 个文件（2.48 MB）到独立目录 F:/mini-OpenClaw-v2。

- 排除：凭据(.env/server-deploy.conf/旧DELIVERY.md)、运行数据(xingbang_data 等
  4 个 SQLite)、依赖(venv/node_modules 符号链接)、归档(_backup*/test-evidence/
  ori_file)、Office 临时文件
- 目标目录独立 git 仓库，初始恢复点；Gitea 远程与分支待 OQ-06 Q2 定案
- 未部署、未启动服务、未调用模型

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

backend/tools/fetch_url_tool.py

@@ -0,0 +1,59 @@
+"""FetchURLTool — Fetch a URL and return cleaned Markdown content."""
+
+from typing import Type
+
+import html2text
+import requests
+from langchain_core.tools import BaseTool
+from pydantic import BaseModel, Field
+
+
+class FetchURLInput(BaseModel):
+    url: str = Field(description="The URL to fetch content from")
+
+
+class FetchURLTool(BaseTool):
+    name: str = "fetch_url"
+    description: str = (
+        "Fetch the content of a web page and return it as cleaned Markdown text. "
+        "Use this to retrieve information from the internet. "
+        "Input should be a valid URL (starting with http:// or https://)."
+    )
+    args_schema: Type[BaseModel] = FetchURLInput
+
+    def _run(self, url: str) -> str:
+        try:
+            headers = {
+                "User-Agent": "Mozilla/5.0 (compatible; MiniOpenClaw/0.1)"
+            }
+            resp = requests.get(url, headers=headers, timeout=15)
+            resp.raise_for_status()
+
+            content_type = resp.headers.get("content-type", "")
+
+            # If JSON, return directly
+            if "application/json" in content_type:
+                text = resp.text
+                if len(text) > 5000:
+                    text = text[:5000] + "\n...[truncated]"
+                return text
+
+            # Convert HTML to Markdown
+            converter = html2text.HTML2Text()
+            converter.ignore_links = False
+            converter.ignore_images = True
+            converter.body_width = 0
+            markdown = converter.handle(resp.text)
+
+            if len(markdown) > 5000:
+                markdown = markdown[:5000] + "\n...[truncated]"
+            return markdown
+
+        except requests.Timeout:
+            return "❌ Request timed out (15s limit)"
+        except requests.RequestException as e:
+            return f"❌ Fetch error: {str(e)}"
+
+
+def create_fetch_url_tool() -> FetchURLTool:
+    return FetchURLTool()