feat: add per-room temperature thresholds

Issue: #487
User-Visible: yes

tests_backend/test_ha_import_export.py

@@ -855,6 +855,7 @@ def _plan_only_source() -> tuple[dict[str, Any], dict[str, Any]]:
         "area": "living-area",
         "settings": {
             "fill_mode": "custom", "custom_fill": {"c": "#123456", "a": 0.4},
+            "temp_min": 18.5, "temp_max": 24,
             "temp_source": "sensor.room_temp", "hum_source": "sensor.room_humidity",
             "future_room_binding": "sensor.secret",
         },
@@ -907,6 +908,7 @@ def test_plan_only_export_projects_geometry_and_round_trips_room_labels(tmp_path
     assert "area" not in room and "future_room" not in room
     assert room["settings"] == {
         "fill_mode": "custom", "custom_fill": {"c": "#123456", "a": 0.4},
+        "temp_min": 18.5, "temp_max": 24,
     }
     opening = exported["openings"][0]
     assert opening["flip_h"] is True
@@ -973,6 +975,10 @@ def test_ordinary_space_export_is_unchanged_when_plan_only_is_false(tmp_path: Pa
     assert implicit == explicit
     assert "plan_only" not in implicit["transfer"]
     assert implicit["payload"]["config"]["markers"]
+    settings = implicit["payload"]["config"]["spaces"][0]["rooms"][0]["settings"]
+    assert settings["temp_min"] == 18.5
+    assert settings["temp_max"] == 24
+    assert settings["future_room_binding"] == "sensor.secret"
     assert set(implicit["payload"]["layout"]) == {
         key for key, pos in layout.items() if pos.get("s") == "ground"
     }

tests_backend/test_validation.py

@@ -1010,6 +1010,21 @@ def test_custom_fill_color_and_alpha_are_strict_on_space_and_room():
             v.SPACE_SCHEMA(room_bad)
 
 
+def test_room_temperature_thresholds_are_optional_strict_finite_numbers():
+    room = {
+        "id": "r1", "name": "R", "x": 0.1, "y": 0.1, "w": 0.2, "h": 0.2,
+        "settings": {"fill_mode": "temp", "temp_min": 0, "temp_max": 24.5},
+    }
+    assert v.ROOM_SCHEMA(room)["settings"]["temp_min"] == 0.0
+    for key in ("temp_min", "temp_max"):
+        nullable = {**room, "settings": {**room["settings"], key: None}}
+        assert v.ROOM_SCHEMA(nullable)["settings"][key] is None
+        for bad in (True, "20", float("nan"), float("inf")):
+            invalid = {**room, "settings": {**room["settings"], key: bad}}
+            with pytest.raises(vol.Invalid):
+                v.ROOM_SCHEMA(invalid)
+
+
 def test_independent_glow_fields_and_legacy_tokens_are_accepted():
     # Current UI writes two independent fields; old dashboard bundles remain
     # valid writers of the legacy enum forever.