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/sidecars/README.md

@@ -435,6 +435,11 @@ Steps, in order:
    searched is kept or logged, and a task's location stays sealed on the person's
    devices.
 
+Todo's forecasts (Halkyon Todo's ADR 0033, D40) come from Open-Meteo through Todo's
+server as Train's workouts' weather does, under the same settings: `WEATHER=off` in
+`deploy/.env` stops both, and `OPEN_METEO_API_KEY` moves both to the paid plan. A device
+asks once a place as the app opens and hourly while it is open.
+
 ## Meditate
 
 Halkyon Meditate's server beside the instance (Halkyon Meditate's ADR 0038, step 7;