feat(train): workouts' weather from Open-Meteo, through the instance (ADR 0036)

A workout with a track gets the weather over it as its page opens, once
while it has none: the hours from the one it started in to the one it
ended in, kept in its sealed payload (temperature, feels-like, humidity,
precipitation, the WMO code, the wind, its gusts and direction) and shown
under its totals with the link to Open-Meteo its licence asks for.

Train's server asks Open-Meteo in the person's place (the `weather`
endpoint), so Open-Meteo never sees their address: the place rounded to
two decimals (also on the phone), a span of at most 48 hours, the
forecast API for recent spans and the archive for older ones, for people
signed in, at most 30 requests a person a minute, nothing kept or
logged. On by default; `WEATHER=off` switches it off, and
`OPEN_METEO_API_KEY` moves it to the paid hosts for an instance used
commercially.

Health Connect's fingerprint leaves the weather out, so keeping it
writes nothing again. No table and no migration.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/train/halkyon_train_flutter/lib/l10n/app_localizations.dart

@@ -4257,6 +4257,84 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'{weight} kg below what was planned'**
   String strengthWeightShort(String weight);
+
+  /// No description provided for @weatherHeading.
+  ///
+  /// In en, this message translates to:
+  /// **'Weather'**
+  String get weatherHeading;
+
+  /// What the sky did over a workout, from Open-Meteo's weather code.
+  ///
+  /// In en, this message translates to:
+  /// **'{conditions, select, clear{Clear} partlyCloudy{Partly cloudy} cloudy{Overcast} fog{Fog} drizzle{Drizzle} rain{Rain} freezingRain{Freezing rain} snow{Snow} rainShowers{Showers} snowShowers{Snow showers} thunderstorm{Thunderstorm} other{Weather}}'**
+  String weatherConditions(String conditions);
+
+  /// No description provided for @weatherTemperature.
+  ///
+  /// In en, this message translates to:
+  /// **'{temperature} °C'**
+  String weatherTemperature(String temperature);
+
+  /// No description provided for @weatherTemperatureRange.
+  ///
+  /// In en, this message translates to:
+  /// **'{low}–{high} °C'**
+  String weatherTemperatureRange(String low, String high);
+
+  /// No description provided for @weatherFeelsLike.
+  ///
+  /// In en, this message translates to:
+  /// **'Felt like {temperature} °C'**
+  String weatherFeelsLike(String temperature);
+
+  /// No description provided for @weatherWind.
+  ///
+  /// In en, this message translates to:
+  /// **'Wind {speed} km/h from the {direction}'**
+  String weatherWind(String speed, String direction);
+
+  /// No description provided for @weatherWindNoDirection.
+  ///
+  /// In en, this message translates to:
+  /// **'Wind {speed} km/h'**
+  String weatherWindNoDirection(String speed);
+
+  /// No description provided for @weatherCalm.
+  ///
+  /// In en, this message translates to:
+  /// **'Hardly any wind'**
+  String get weatherCalm;
+
+  /// No description provided for @weatherGusts.
+  ///
+  /// In en, this message translates to:
+  /// **'gusts up to {speed} km/h'**
+  String weatherGusts(String speed);
+
+  /// Where the wind came from, as in "from the south-west".
+  ///
+  /// In en, this message translates to:
+  /// **'{direction, select, n{north} ne{north-east} e{east} se{south-east} s{south} sw{south-west} w{west} nw{north-west} other{wind}}'**
+  String weatherDirection(String direction);
+
+  /// No description provided for @weatherPrecipitation.
+  ///
+  /// In en, this message translates to:
+  /// **'{amount} mm fell'**
+  String weatherPrecipitation(String amount);
+
+  /// No description provided for @weatherDry.
+  ///
+  /// In en, this message translates to:
+  /// **'Nothing fell'**
+  String get weatherDry;
+
+  /// No description provided for @weatherBy.
+  ///
+  /// In en, this message translates to:
+  /// **'Weather data by Open-Meteo.com'**
+  String get weatherBy;
 }
 
 class _AppLocalizationsDelegate