What does this PR do?

The Honcho memory plugin reads HONCHO_BASE_URL from an environment
variable and passes it directly to the Honcho client without validation.

If HONCHO_BASE_URL is set to an internal address (e.g.
http://169.254.169.254 on AWS, http://metadata.google.internal on GCP,
or any private network service), every memory read and write would silently
make requests to that internal address — a classic SSRF attack vector.

Fix

Added an is_safe_url() check after reading HONCHO_BASE_URL. If the
URL resolves to a private/internal address, it is ignored with a warning
log and the plugin falls back to API-key-only mode.

This is consistent with the SSRF protection already applied in:

• tools/homeassistant_tool.py (HASS_URL)
• plugins/memory/retaindb/__init__.py (RETAINDB_BASE_URL)
• tools/web_tools.py

Type of Change

• 🔒 Security fix (SSRF)

Checklist

• Read the Contributing Guide
• Commit messages follow Conventional Commits
• Consistent with existing SSRF protection pattern in Hermes
• No behavior change for legitimate Honcho endpoints
• ImportError handled gracefully