feat(config): ajouter la configuration Home Assistant (étape 1)

Ajoute la section [home_assistant] au TOML et sa validation au chargement
via get_home_assistant_config(). La section est facultative pour préserver
la compatibilité avec les configurations existantes, mais si elle est
présente elle doit être complète et référencer un type de journée, un
trajet et un véhicule à moteur existants, sous peine de refuser le
démarrage de l'application. La configuration validée est exposée dans
app.config['HOME_ASSISTANT'].

Co-authored-by: OpenAI/GPT-5.6-Luna-Pro <vibecoder@antoineve.me>

tests/test_config_loader.py

@@ -1,3 +1,34 @@
+import pytest
+
+from app import create_app
+
+_MINIMAL_CONFIG = """
+[vehicles.citadine]
+name = "Citadine"
+type = "moteur"
+
+[vehicles.velo]
+name = "Vélo"
+type = "velo"
+
+[journeys.moteur_seul]
+name = "Moteur seul"
+distances = {{ moteur = 1 }}
+
+[home_assistant]
+timezone = "{timezone}"
+default_day_type = "{day_type}"
+default_journey_profile_id = "{journey_id}"
+default_motor_vehicle_id = "{vehicle_id}"
+"""
+
+
+def _create_app_with_home_assistant_config(tmp_path, **values):
+    config_path = tmp_path / "config.toml"
+    config_path.write_text(_MINIMAL_CONFIG.format(**values), encoding="utf-8")
+    return create_app(config_path=str(config_path))
+
+
 def test_get_vehicles_returns_configured_vehicles(app):
     with app.app_context():
         from app.config_loader import get_vehicles
@@ -59,3 +90,78 @@ def test_day_types_without_journey(app):
         types = day_types_without_journey()
         assert "TT" in types
         assert "WORK" not in types
+
+
+def test_get_home_assistant_config_returns_validated_defaults(app):
+    with app.app_context():
+        from app.config_loader import get_home_assistant_config
+
+        assert get_home_assistant_config() == {
+            "timezone": "Europe/Paris",
+            "default_day_type": "WORK",
+            "default_journey_profile_id": "moteur_seul",
+            "default_motor_vehicle_id": "citadine",
+        }
+        assert app.config["HOME_ASSISTANT"]["default_motor_vehicle_id"] == "citadine"
+
+
+def test_home_assistant_section_absent_is_allowed(app):
+    with app.app_context():
+        from app.config_loader import get_home_assistant_config
+
+        app.config["TOML"].pop("home_assistant")
+        assert get_home_assistant_config() is None
+
+
+@pytest.mark.parametrize(
+    ("field", "value", "message"),
+    [
+        ("timezone", "Mars/NoSuchPlace", "fuseau horaire"),
+        ("day_type", "UNKNOWN", "type de journée"),
+        ("journey_id", "unknown_journey", "trajet inconnu"),
+        ("vehicle_id", "unknown_vehicle", "véhicule inconnu"),
+    ],
+)
+def test_invalid_home_assistant_config_prevents_startup(tmp_path, field, value, message):
+    values = {
+        "timezone": "Europe/Paris",
+        "day_type": "WORK",
+        "journey_id": "moteur_seul",
+        "vehicle_id": "citadine",
+    }
+    values[field] = value
+
+    with pytest.raises(ValueError, match=message):
+        _create_app_with_home_assistant_config(tmp_path, **values)
+
+
+def test_home_assistant_default_vehicle_must_be_motor_vehicle(tmp_path):
+    values = {
+        "timezone": "Europe/Paris",
+        "day_type": "WORK",
+        "journey_id": "moteur_seul",
+        "vehicle_id": "velo",
+    }
+
+    with pytest.raises(ValueError, match="véhicule moteur"):
+        _create_app_with_home_assistant_config(tmp_path, **values)
+
+
+def test_incomplete_home_assistant_config_prevents_startup(tmp_path):
+    config_path = tmp_path / "config.toml"
+    config_path.write_text(
+        """
+[vehicles.citadine]
+type = "moteur"
+
+[journeys.moteur_seul]
+distances = { moteur = 1 }
+
+[home_assistant]
+timezone = "Europe/Paris"
+""",
+        encoding="utf-8",
+    )
+
+    with pytest.raises(ValueError, match="clé.*manquante"):
+        create_app(config_path=str(config_path))