Fix saved layouts silently dropping weather widget settings

LAYOUT_CONFIG_FIELDS never had a "weather" entry, so saving a layout
captured an empty config for any weather widget -- applying it back
(including via hold-to-cycle) reset mode/provider/city/units/etc to
defaults instead of restoring what was configured.

server/app/routers/api_layouts.py

@@ -63,6 +63,10 @@ LAYOUT_CONFIG_FIELDS: dict[str, tuple[str, ...]] = {
     "text": ("content", "font_size", "font_family", "align", "background_color"),
     "whiteboard": ("user_id", "url"),
     "battery": ("mode",),
+    "weather": (
+        "mode", "provider", "units", "city_label", "city_latitude", "city_longitude",
+        "hourly_interval_hours", "daily_days", "cities",
+    ),
 }
 
 # widget_type -> (FrameCalendar|FrameTaskList model, SavedLayoutSource.kind)

server/tests/test_saved_layouts.py

@@ -27,6 +27,7 @@ from app.models import (
     TaskWidgetConfig,
     User,
     Widget,
+    WeatherWidgetConfig,
 )
 
 from .conftest import csrf_headers, link_user, login, make_user
@@ -56,6 +57,16 @@ def _add_tasks_widget(db_session, frame_id=1, x=3, y=0, w=2, h=2, sort_order=2)
     return widget
 
 
+def _add_weather_widget(db_session, frame_id=1, x=0, y=0, w=2, h=2, sort_order=1) -> Widget:
+    widget = Widget(frame_id=frame_id, widget_type="weather", x=x, y=y, w=w, h=h,
+                    sort_order=sort_order, created_at=time.time())
+    db_session.add(widget)
+    db_session.flush()
+    db_session.add(WeatherWidgetConfig(widget_id=widget.id))
+    db_session.commit()
+    return widget
+
+
 def _setup_alice(client) -> None:
     resp = client.post("/setup", data={"username": "alice", "password": "hunter22"})
     assert resp.status_code == 303, resp.text
@@ -89,6 +100,48 @@ def test_save_captures_placement_and_photo_settings_but_not_queue_state(client,
                            "queue_target_len": 30}
 
 
+def test_save_and_apply_round_trip_weather_settings(client, db_session):
+    _setup_alice(client)
+    weather = _add_weather_widget(db_session)
+    with db_session.no_autoflush:
+        wcfg = db_session.get(WeatherWidgetConfig, weather.id)
+        wcfg.mode = "daily"
+        wcfg.provider = "nws"
+        wcfg.units = "celsius"
+        wcfg.city_label = "Boston, MA"
+        wcfg.city_latitude = 42.36
+        wcfg.city_longitude = -71.06
+        wcfg.hourly_interval_hours = 6
+        wcfg.daily_days = 7
+        wcfg.checked_at = 12345.0
+        wcfg.cached = {"stale": "runtime state, not a setting"}
+    db_session.commit()
+    db_session.expunge(wcfg)
+
+    save_resp = client.post("/api/frames/1/layouts", json={"name": "Weather Layout"}, headers=csrf_headers(client))
+    assert save_resp.status_code == 200, save_resp.text
+    layout = db_session.query(SavedLayout).filter_by(user_id=1, name="Weather Layout").one()
+    snap = db_session.query(SavedLayoutWidget).filter_by(saved_layout_id=layout.id, widget_type="weather").one()
+    assert snap.config == {
+        "mode": "daily", "provider": "nws", "units": "celsius", "city_label": "Boston, MA",
+        "city_latitude": 42.36, "city_longitude": -71.06, "hourly_interval_hours": 6, "daily_days": 7,
+        "cities": None,
+    }
+
+    client.delete("/api/frames/1/widgets", headers=csrf_headers(client))
+    apply_resp = client.post(f"/api/frames/1/layouts/{layout.id}/apply", headers=csrf_headers(client))
+    assert apply_resp.status_code == 200, apply_resp.text
+
+    new_widget = db_session.query(Widget).filter_by(frame_id=1, widget_type="weather").one()
+    new_cfg = db_session.get(WeatherWidgetConfig, new_widget.id)
+    assert (new_cfg.mode, new_cfg.provider, new_cfg.units) == ("daily", "nws", "celsius")
+    assert (new_cfg.city_label, new_cfg.city_latitude, new_cfg.city_longitude) == ("Boston, MA", 42.36, -71.06)
+    assert (new_cfg.hourly_interval_hours, new_cfg.daily_days) == (6, 7)
+    # Runtime fetch-cache state is never captured/restored by a saved layout.
+    assert new_cfg.checked_at == 0.0
+    assert new_cfg.cached is None
+
+
 def test_save_captures_calendar_sources_and_button_actions(client, db_session):
     _setup_alice(client)
     db_session.query(Widget).filter_by(frame_id=1, widget_type="photos").delete()