test: Drop diagnostics and unused coverage path mapping

conftest.py (root) is the actual fix; remove the DIAG print and the
[paths]/relative_files left over from the abandoned site-packages
measurement approach.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: davidparsson

.coveragerc

@@ -1,11 +1,3 @@
-[run]
-relative_files = true
-
-[paths]
-source =
-    injector/
-    */site-packages/injector/
-
 [report]
 exclude_also =
     if TYPE_CHECKING:

conftest.py

@@ -1,6 +1,6 @@
-import sys
-
-
-def pytest_collection_finish(session):
-    m = sys.modules.get("injector")
-    print("DIAG executed-injector:", getattr(m, "__file__", m))
+# This file exists so that pytest inserts the repository root at the front of
+# sys.path before coverage starts measuring. Without it, running the `pytest`
+# console script with the package installed makes `--cov=injector` bind to the
+# installed site-packages copy, while the tests import the working-tree copy --
+# so no executed lines are measured and coverage is reported as 0%.
+# See https://github.com/pytest-dev/pytest-cov/issues/98