fix(ci): la collecte des tests échouait sous le binaire pytest

from tests.conftest import ... levait ModuleNotFoundError en CI :
le binaire pytest n'ajoute pas le répertoire courant à sys.path,
contrairement à python -m pytest (utilisé en local, qui masquait le
problème). Correctifs : tests/__init__.py (package), pythonpath=[.]
dans la config pytest, et étape CI en python -m pytest.
Vérifié : 36/36 dans les trois modes d'invocation.

.gitea/workflows/ci.yml

@@ -17,4 +17,4 @@ jobs:
       - name: Compile check
         run: python -m py_compile app/*.py
       - name: Tests
-        run: pytest -q
+        run: python -m pytest -q

pyproject.toml

@@ -24,3 +24,7 @@ dev = [
 [tool.pytest.ini_options]
 testpaths = ["tests"]
 asyncio_mode = "auto"
+# Always put the repo root on sys.path: the plain `pytest` binary (CI)
+# does not add the CWD, unlike `python -m pytest` — without this,
+# `from tests.conftest import ...` fails at collection time in CI.
+pythonpath = ["."]

tests/__init__.py

@@ -0,0 +1,8 @@
+"""Kanbante test suite.
+
+This package marker matters: with it, pytest puts the repository root on
+sys.path, so `from tests.conftest import ...` resolves identically
+whether the suite is launched via the `pytest` binary (CI) or via
+`python -m pytest` (which additionally adds the CWD). The root is also
+pinned explicitly through `pythonpath` in pyproject.toml.
+"""