Étape 5 : API CRUD, matrice et validation branchée

- CRUD complet, scopé par édition, sur Position, Shift, Volunteer, Assignment
  (routers app/api/*, schémas Pydantic, dépendance get_edition partagée)
- Volunteer : gestion des compétences par codes (création à la volée),
  suppression = effacement complet en cascade (RGPD)
- Shift : contrôle fin > début, poste de la même édition, compétences requises
- Assignment : toute écriture active passe par le moteur de validation ;
  violation bloquante -> 422 error.validation_failed, avertissements renvoyés
  dans la réponse. Endpoint POST .../assignments/validate en simulation.
  app/validation/loader.py construit la ValidationInput depuis la base.
- GET /editions/{id}/matrix : postes -> créneaux -> {min, ideal, confirmed,
  proposed}, source de l'écran principal
- 30 tests d'API (CRUD, 404/409/422, cascade, blocage, avertissements, matrice,
  loader) ; 104 tests au total ; alembic check toujours vert
- Clés de traduction shift.* / assignment.* / volunteer.* ajoutées

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017uUsRg7XzopkCPWimwg9ZM

backend/tests/test_api_shifts.py

@@ -0,0 +1,100 @@
+import datetime as dt
+
+from tests.factories import make_position
+
+
+def _url(edition, suffix=""):
+    return f"/editions/{edition.id}/shifts{suffix}"
+
+
+def _payload(position, **overrides):
+    base = {
+        "position_id": str(position.id),
+        "starts_at": "2026-07-10T18:00:00",
+        "ends_at": "2026-07-10T22:00:00",
+        "min_staff": 2,
+        "ideal_staff": 4,
+        "required_skill_codes": ["SST"],
+    }
+    base.update(overrides)
+    return base
+
+
+def test_create_shift_with_required_skills(client, edition, session):
+    position = make_position(session, edition)
+    resp = client.post(_url(edition), json=_payload(position))
+    assert resp.status_code == 201
+    body = resp.json()
+    assert body["required_skill_codes"] == ["SST"]
+    assert body["min_staff"] == 2
+    assert body["position_id"] == str(position.id)
+
+
+def test_create_shift_end_before_start_is_422(client, edition, session):
+    position = make_position(session, edition)
+    resp = client.post(
+        _url(edition),
+        json=_payload(position, ends_at="2026-07-10T17:00:00"),
+    )
+    assert resp.status_code == 422
+    assert resp.json()["detail"]["code"] == "shift.ends_not_after_starts"
+
+
+def test_create_shift_with_position_from_other_edition_is_422(client, edition, session):
+    from app.models import Edition
+
+    other = Edition(
+        year=2027, start_date=dt.date(2027, 7, 1), end_date=dt.date(2027, 7, 4)
+    )
+    session.add(other)
+    session.commit()
+    session.refresh(other)
+    stranger_position = make_position(session, other)
+
+    resp = client.post(_url(edition), json=_payload(stranger_position))
+    assert resp.status_code == 422
+    assert resp.json()["detail"]["code"] == "shift.position_wrong_edition"
+
+
+def test_list_filter_by_position(client, edition, session):
+    p1 = make_position(session, edition, name="P1")
+    p2 = make_position(session, edition, name="P2")
+    client.post(_url(edition), json=_payload(p1))
+    client.post(
+        _url(edition),
+        json=_payload(
+            p2,
+            starts_at="2026-07-11T09:00:00",
+            ends_at="2026-07-11T12:00:00",
+        ),
+    )
+
+    only_p1 = client.get(_url(edition), params={"position_id": str(p1.id)}).json()
+    assert len(only_p1) == 1
+    assert only_p1[0]["position_id"] == str(p1.id)
+    assert len(client.get(_url(edition)).json()) == 2
+
+
+def test_patch_shift_times_and_skills(client, edition, session):
+    position = make_position(session, edition)
+    sid = client.post(_url(edition), json=_payload(position)).json()["id"]
+
+    patched = client.patch(
+        _url(edition, f"/{sid}"),
+        json={
+            "ends_at": "2026-07-10T23:30:00",
+            "required_skill_codes": ["SOUND", "SST"],
+        },
+    )
+    assert patched.status_code == 200
+    assert patched.json()["ends_at"] == "2026-07-10T23:30:00"
+    assert patched.json()["required_skill_codes"] == ["SOUND", "SST"]
+
+
+def test_patch_shift_into_invalid_range_is_422(client, edition, session):
+    position = make_position(session, edition)
+    sid = client.post(_url(edition), json=_payload(position)).json()["id"]
+    resp = client.patch(
+        _url(edition, f"/{sid}"), json={"starts_at": "2026-07-11T00:00:00"}
+    )
+    assert resp.status_code == 422