trip: include transit airport cities in destination timezone list

Transit countries (e.g. Madrid on the Peru trip) were already included
in trip.countries via flight data, but get_destination_timezones only
iterated trip.locations() which comes from accommodation/conferences/events.
Now also extract airport cities from flights and append any that aren't
already covered by a stay, using the airport coordinates for timezone lookup.

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

web_view.py

@@ -887,10 +887,46 @@ def get_destination_timezones(trip: Trip) -> list[StrDict]:
             if candidate:
                 per_location[key].append(candidate)
 
+    # Also collect airport locations from flights, for transit countries
+    flight_locations: list[tuple[str, Country]] = []
+    seen_flight_keys: set[tuple[str, str]] = set()
+    for item in trip.travel:
+        if item.get("type") != "flight":
+            continue
+        for airport_key in ("from_airport", "to_airport"):
+            airport = item.get(airport_key)
+            if not isinstance(airport, dict):
+                continue
+            city = airport.get("city")
+            country_code = airport.get("country")
+            if not isinstance(city, str) or not isinstance(country_code, str):
+                continue
+            if country_code == "gb":
+                continue
+            key = (city, country_code.lower())
+            lat = airport.get("latitude")
+            lon = airport.get("longitude")
+            if isinstance(lat, (int, float)) and isinstance(lon, (int, float)):
+                location_coords.setdefault(key, (float(lat), float(lon)))
+            if key not in seen_flight_keys:
+                seen_flight_keys.add(key)
+                flight_country = agenda.get_country(country_code)
+                if flight_country:
+                    flight_locations.append((city, flight_country))
+
+    existing_location_keys = {
+        (loc, c.alpha_2.lower()) for loc, c in trip.locations()
+    }
+    all_locations = list(trip.locations()) + [
+        (city, country)
+        for city, country in flight_locations
+        if (city, country.alpha_2.lower()) not in existing_location_keys
+    ]
+
     destination_times: list[StrDict] = []
     trip_end = trip.end or trip.start
 
-    for location, country in trip.locations():
+    for location, country in all_locations:
         country_code = country.alpha_2.lower()
         key = (location, country_code)
         timezone_name = None