ci(backend): ignore queryargus submodule tests during pytest collection

The submodule's tests require extras (azure-*, typer) that CI deliberately
skips via `pip install --no-deps -e ./queryargus`, so collecting them fails
on CI. Add `--ignore=queryargus` so pytest only walks the BFF's own tests.
The submodule has its own CI; we don't need to re-run those tests here.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: ChingEnLin

backend/pytest.ini

@@ -3,7 +3,7 @@ testpaths = tests
 python_files = test_*.py
 python_classes = Test*
 python_functions = test_*
-addopts = 
+addopts =
     --strict-markers
     --strict-config
     --verbose
@@ -12,6 +12,7 @@ addopts =
     --cov-report=html
     --cov-exclude=tests/*
     --cov-exclude=queryargus/*
+    --ignore=queryargus
 markers =
     unit: Unit tests
     integration: Integration tests