feat(todo): Todo's server answers a place's forecast (ADR 0033, D40)

The weather of D40 comes through the instance, as Train's workouts'
(ADR 0036, D1): Todo's server gets a `weather` endpoint, `offered` and
`forecast`, answering a place's hours for the next 16 days from
Open-Meteo for people signed in alone, the place rounded to about a
kilometre, nothing kept or logged, 30 requests a person a minute.
Refusals are `WeatherRefused` (off, invalid, tooOften, unreachable).
`WEATHER=off` and `OPEN_METEO_API_KEY` switch it as they switch Train's,
and production's compose file passes them to Todo's server too.

D40 records the developer's decisions of 10 Nov 2026 on the weather and
the agent's details (what dry, sunny, a temperature range and calm mean
over a task's hours).

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

deploy/compose.todo.yaml

@@ -37,6 +37,10 @@ services:
       SOURCE_URL: ${SOURCE_URL:-}
       DATA_LOCATION: ${DATA_LOCATION:-}
       BACKUP_LOCATION: ${BACKUP_LOCATION:-}
+      # Forecasts from Open-Meteo (ADR 0033, D40), as Train's workouts' weather:
+      # on unless `off`; a key for its paid host where used commercially.
+      WEATHER: ${WEATHER:-}
+      OPEN_METEO_API_KEY: ${OPEN_METEO_API_KEY:-}
     networks:
       - default
       - edge