🛡️ Sentinel: [HIGH] Fix Server-Side Request Forgery in IMAP connections

🚨 Severity: HIGH
💡 Vulnerability: User-provided IMAP `host` in `_test_imap_connection` and `pull_inbox` was not validated against private IPs, creating an SSRF risk.
🎯 Impact: Attackers could abuse the endpoints to port-scan or interact with internal/private network services.
🔧 Fix: Integrated `is_private_ip` from `app.utils.network` to block connections resolving to private, loopback, link-local, or reserved IPs.
✅ Verification: Ran `test_imap_tasks.py` and `test_api_imap_accounts.py` successfully. Checked `ruff` output and diffs. Removed all scratch files from the commit.

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

tests/test_coverage_remaining_gaps.py

@@ -69,9 +69,8 @@ class TestViewsBase:
             context = {"request": req}
             template_response_with_version("template.html", context)
 
-        args, kwargs = mock_orig.call_args
-        context = kwargs.get("context", {})
-        assert context.get("csrf_token") == "my-csrf"
+        args, _ = mock_orig.call_args
+        assert args[1].get("csrf_token") == "my-csrf"
 
     def test_kwargs_context_no_request(self):
         """Test kwargs context path when request is not in context."""