Add weather to calendar mode; fix CalDAV events never showing

Weather: multiple cities per frame, geocoded via Open-Meteo (no API
key), shown above the event list on agenda/today & tomorrow/week views
-- never month, no room for it there. Hand-drawn sun/cloud/rain/snow/
thunderstorm icons (no new font/icon asset, same primitives-only
approach the rest of calendar_render.py already uses). City geocoding
handles "City, State" qualifiers Open-Meteo's own search doesn't
(disambiguates same-named cities, e.g. the three "Portland"s).

CalDAV fix: events were never showing despite calendars discovering
fine, because fetch_calendar_events relied on the calendar-query
REPORT's server-side time-range filter, which real servers implement
inconsistently (confirmed against a real server, not just guessed --
reproduced locally with Radicale). Switched to fetching every event
unfiltered and doing all date-window filtering/expansion client-side,
same approach already used for plain ICS feeds.

server/app/routers/api_frames.py

@@ -25,7 +25,7 @@ from pydantic import BaseModel
 from sqlalchemy import select
 from sqlalchemy.orm import Session
 
-from .. import calendar_render, gitea_releases, photo_queue, quiet_hours
+from .. import calendar_render, gitea_releases, photo_queue, quiet_hours, weather
 from ..auth import require_frame_control, require_frame_view, require_user_api
 from ..db import frame_locked, get_db
 from ..image_pipeline import (
@@ -44,6 +44,7 @@ from .common import (
     calendar_sources_for_frame,
     fetch_source_and_faces,
     get_or_refresh_calendar_events,
+    get_or_refresh_weather,
     immich_client_for,
     immich_creds,
     list_assets,
@@ -100,6 +101,8 @@ def api_config_save(
     calendar_view: str | None = Form(None),
     calendar_photo_inlay: bool | None = Form(None),
     calendar_week_start: int | None = Form(None),
+    calendar_weather_enabled: bool | None = Form(None),
+    calendar_weather_units: str | None = Form(None),
     frame: Frame = Depends(require_frame_control),
     db: Session = Depends(get_db),
 ):
@@ -177,6 +180,14 @@ def api_config_save(
             cfg.calendar_photo_inlay = calendar_photo_inlay
         if calendar_week_start is not None:
             cfg.calendar_week_start = max(0, min(6, calendar_week_start))
+        if calendar_weather_enabled is not None:
+            cfg.calendar_weather_enabled = calendar_weather_enabled
+        if calendar_weather_units is not None and calendar_weather_units in ("fahrenheit", "celsius"):
+            if calendar_weather_units != cfg.calendar_weather_units:
+                # Cached forecasts are in the old unit -- force a refetch
+                # rather than showing stale numbers under a new unit label.
+                cfg.calendar_weather_checked_at = 0.0
+            cfg.calendar_weather_units = calendar_weather_units
         cfg.stats_config_saves += 1
     return {"status": "saved"}
 
@@ -497,14 +508,62 @@ def api_preview_calendar(frame: Frame = Depends(require_frame_view), db: Session
     events, summary = get_or_refresh_calendar_events(db, frame)
     photo_inlay = _calendar_photo_inlay(frame, db)
     view = frame.calendar_view if frame.calendar_view in calendar_render.CALENDAR_VIEWS else "agenda"
+    weather_cities = get_or_refresh_weather(db, frame)
     png = calendar_render.render_calendar_preview_png(
         events, view=view, browse_offset=frame.calendar_browse_offset, orientation=frame.orientation,
         palette_rgb=frame.palette_rgb, timezone=frame.timezone, photo_inlay=photo_inlay, fetch_summary=summary,
         week_start=frame.calendar_week_start,
+        weather_cities=weather_cities, weather_units=frame.calendar_weather_units,
     )
     return Response(content=png, media_type="image/png")
 
 
+class WeatherCityAddRequest(BaseModel):
+    name: str
+
+
+@router.post("/api/frames/{frame_id}/weather-cities/add")
+def api_weather_city_add(
+    body: WeatherCityAddRequest,
+    frame: Frame = Depends(require_frame_control),
+    db: Session = Depends(get_db),
+):
+    """Geocodes a free-text city name (e.g. "Portland, OR") and adds it
+    to this frame's weather strip -- a frame-wide display setting (like
+    calendar_view), not personal data, so this is gated the same way as
+    api_config_save rather than the calendar-select owner/mute split."""
+    try:
+        city = weather.geocode_city(body.name)
+    except weather.WeatherFetchError as e:
+        raise HTTPException(400, str(e)) from e
+    with frame_locked(db, frame.id) as cfg:
+        cities = list(cfg.calendar_weather_cities or [])
+        if any(c["label"] == city["label"] for c in cities):
+            raise HTTPException(400, f"{city['label']} is already on this frame's list")
+        cities.append(city)
+        cfg.calendar_weather_cities = cities
+        cfg.calendar_weather_checked_at = 0.0  # pick up the new city promptly
+    return {"status": "saved", "city": city}
+
+
+class WeatherCityRemoveRequest(BaseModel):
+    label: str
+
+
+@router.post("/api/frames/{frame_id}/weather-cities/remove")
+def api_weather_city_remove(
+    body: WeatherCityRemoveRequest,
+    frame: Frame = Depends(require_frame_control),
+    db: Session = Depends(get_db),
+):
+    with frame_locked(db, frame.id) as cfg:
+        cities = [c for c in (cfg.calendar_weather_cities or []) if c["label"] != body.label]
+        cfg.calendar_weather_cities = cities
+        cached = [c for c in (cfg.calendar_weather_cached or []) if c["label"] != body.label]
+        cfg.calendar_weather_cached = cached
+    return {"status": "saved"}
+
+
 @router.post("/api/frames/{frame_id}/firmware")
 def api_firmware_upload(
     file: UploadFile = File(...),