feat(client): filter select_recipe by STATION_CODE with error fallback

Replace generic /api/recipes call with api_client.get_station_recipes(STATION_CODE).
Return 503 station_not_configured.html when STATION_CODE env var is unset.
Add station indicator to recipe selection page header.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/tests/test_measure.py

@@ -8,15 +8,18 @@ import pytest
 class TestSelectRecipe:
     """GET /measure/select tests."""
 
-    def test_select_recipe_renders(self, logged_in_client, mock_api_client):
+    def test_select_recipe_renders(self, logged_in_client, mock_api_client, monkeypatch):
         """Recipe selection page renders for MeasurementTec role."""
-        mock_api_client.get.return_value = {
-            "items": [
-                {"id": 1, "code": "REC-001", "name": "Test Recipe"},
-            ],
-            "total": 1,
-            "pages": 1,
-        }
+        monkeypatch.setenv("STATION_CODE", "ST-TEST")
+        import config
+        import importlib
+        importlib.reload(config)
+        import blueprints.measure
+        importlib.reload(blueprints.measure)
+
+        mock_api_client.get_station_recipes.return_value = [
+            {"id": 1, "code": "REC-001", "name": "Test Recipe"},
+        ]
 
         resp = logged_in_client.get("/measure/select")
         assert resp.status_code == 200

client/tests/test_measure_station_filter.py

@@ -0,0 +1,37 @@
+"""Verify that /measure/select reads STATION_CODE and filters recipes via the server."""
+import importlib
+from unittest.mock import patch, MagicMock
+
+
+def _reload_measure(monkeypatch, station_code=None):
+    """Reload config and measure module under the given STATION_CODE env."""
+    if station_code is None:
+        monkeypatch.delenv("STATION_CODE", raising=False)
+    else:
+        monkeypatch.setenv("STATION_CODE", station_code)
+    import config
+    importlib.reload(config)
+    import blueprints.measure
+    importlib.reload(blueprints.measure)
+
+
+def test_select_recipe_calls_station_endpoint(logged_in_client, monkeypatch):
+    _reload_measure(monkeypatch, station_code="ST-TEST")
+    from blueprints import measure as measure_bp_mod
+    with patch.object(measure_bp_mod, "api_client") as mock_api:
+        mock_api.get_station_recipes.return_value = [
+            {"id": 1, "code": "R1", "name": "Recipe 1", "active": True},
+        ]
+        resp = logged_in_client.get("/measure/select")
+        assert resp.status_code == 200
+        mock_api.get_station_recipes.assert_called_once()
+        args, kwargs = mock_api.get_station_recipes.call_args
+        assert args[0] == "ST-TEST" or kwargs.get("station_code") == "ST-TEST"
+
+
+def test_select_recipe_without_station_code_shows_error(logged_in_client, monkeypatch):
+    _reload_measure(monkeypatch, station_code=None)
+    resp = logged_in_client.get("/measure/select")
+    assert resp.status_code == 503
+    body = resp.data.lower()
+    assert b"station_code" in body or b"stazione" in body