Bug: SSRF guard blocks ALL external URLs when using local proxy (Clash/Tunnel)

Issue Description

When OpenClaw is configured with a local proxy (e.g., Clash on port 7890), the SSRF guard blocks nearly ALL external URL fetches, making core functionality unusable.

Root cause: Clash's fake-IP DNS returns private IP addresses (198.18.x.x or 127.0.0.1) for ALL hostnames. OpenClaw's SSRF security check rejects these as "Blocked hostname: private/internal/special-use IP address".

Affected Channels & Tools

1. Telegram media downloads — Users cannot send screenshots

   • Error: "Failed to download media. Please try again."
   • Log: [security] blocked URL fetch target=https://api.telegram.org/file/... reason=Blocked hostname (not in allowlist): 127.0.0.1
   • Known issue: [Bug] Telegram media download fails: proxy users api.telegram.org resolves to 127.0.0.1, SSRF blocks it #62539 (still OPEN)

2. WeChat connectivity — WeChat channel cannot poll for updates

   • Error: [openclaw-weixin] weixin getUpdates error: fetch failed

3. web_fetch / url-fetch tool — BROKEN

   • 1,600+ blocked fetches in a single day
   • Affects ALL web research, content extraction, knowledge base building
   • Blocked: zhihu.com, xiaohongshu.com, youtube.com, github.com, etc.

4. wechat-search skill — Cannot search WeChat articles

5. agent-reach skill — Cannot fetch external platform content

Environment

• OpenClaw: 2026.4.5
• Proxy: Clash (ClashX/ClashMac) on localhost:7890
• Proxy mode: enhanced-mode: fake-ip (default Clash DNS)

Attempted Fixes (All Failed)

1. channels.telegram.network.dangerouslyAllowPrivateNetwork: true — No effect
2. channels.telegram.network.allowedHostnames: ["*.telegram.org"] — No effect
3. channels.telegram.network.hostnameAllowlist: ["*.telegram.org"] — No effect
4. Adding 127.0.0.1 to hostnameAllowlist — No effect
5. Clash fake-ip-filter: +.telegram.org — No effect

Why This Affects ALL Proxy Users

Any user running a VPN/proxy with fake-IP DNS (Clash, Surge, Stash, etc.) will hit this. This is extremely common in China where direct international connections are unavailable.

Suggested Fixes

Option 1 (simplest): Trust loopback proxy for all requests
When a request is explicitly routed through a configured proxy, the SSRF guard should not apply. The proxy is already a trusted gateway.

Option 2: Add safe hostnames to default allowlist
api.telegram.org, cdn.telegram.org, mp.weixin.qq.com, etc.

Option 3: Bypass SSRF for proxied HTTPS requests
Trust the proxy to handle DNS correctly for explicitly proxied requests.

Impact

This makes OpenClaw effectively unusable for its core knowledge-work automation use case.