🔧 Update coverage configuration and simplify test script (#1867)

backend/pyproject.toml

@@ -67,3 +67,14 @@ ignore = [
 [tool.ruff.lint.pyupgrade]
 # Preserve types, even if a file imports `from __future__ import annotations`.
 keep-runtime-typing = true
+
+[tool.coverage.run]
+source = ["app"]
+dynamic_context = "test_function"
+
+[tool.coverage.report]
+show_missing = true
+sort = "-Cover"
+
+[tool.coverage.html]
+show_contexts = true