Harden web_fetch SSRF and tool-renderer XSS guards

[daiv-agent]

This change hardens two security boundaries: the web_fetch middleware's SSRF protection now resolves DNS to catch rebinding and non-dotted IP encodings, and the chat tool-body renderer escapes quotes and gates non-http(s) URLs so attacker-controlled URLs cannot become script sinks in the DOM.

Key Changes:

• Added _ip_is_blocked in daiv/automation/agent/middlewares/web_fetch.py, which unwraps v4-mapped/v4-compatible IPv6 addresses before checking private/loopback/link-local/reserved/multicast.
• Added async _resolved_addresses_are_blocked, which resolves hostnames via asyncio.to_thread(socket.getaddrinfo) and blocks if any resolved address is internal — closing the DNS-rebinding gap and catching decimal/hex/octal IPv4 encodings the literal fast path treats as hostnames.
• _fetch_url_text now checks both the string fast path and the resolver on every request (including redirects), and rejects cross-host redirects to non-http(s) schemes before the Location header is embedded in the <redirect_url> tag.
• In daiv/chat/static/chat/js/tool-renderers.js, escapeHtml now also escapes double and single quotes, and externalLink renders only http:/https: URLs as anchors — javascript:/data: URLs become plain escaped text spans.
• toolBodyHTML now routes its output through window.DOMPurify.sanitize (with FORBID_TAGS for style/form/input/button/iframe/object/embed) as the final security boundary before it feeds x-html.
• Added tests/unit_tests/automation/agent/middlewares/test_web_fetch_ssrf.py cases (DNS-rebind to loopback/link-local/v4-mapped/unique-local, public pass-through, non-http(s) redirect blocking, same-host re-resolution) and new tests/unit_tests/chat/test_tool_renderers_xss.py + tool_renderers_driver.py that run the real tool-renderers.js under node.

---

⚠️ DAIV can make mistakes. Please review the changes and merge the MR if everything looks good.
🔗 Generated by DAIV — view sessions

---

💡 Instructions for the reviewer:

• 💬 Just leave comments/reviews mentioning @daiv-agent to get DAIV to address them for you.