🛡️ 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_dark_mode.py

@@ -55,8 +55,8 @@ class TestDarkModeTemplateInjection:
 
         captured = {}
 
-        def fake_original(request_obj, name, context=None, **kw):
-            captured.update(context or {})
+        def fake_original(name, ctx, **kw):
+            captured.update(ctx)
 
         with patch("app.views.base.original_template_response", side_effect=fake_original):
             mock_request = MagicMock()
@@ -73,8 +73,8 @@ class TestDarkModeTemplateInjection:
 
         captured = {}
 
-        def fake_original(request_obj, name, context=None, **kw):
-            captured.update(context or {})
+        def fake_original(name, ctx, **kw):
+            captured.update(ctx)
 
         with patch("app.views.base.original_template_response", side_effect=fake_original):
             mock_request = MagicMock()