Wrap a Task.Supervisor in a PartitionSupervisor (one partition per
scheduler) and route the four sustained async_stream callers through
`{:via, PartitionSupervisor, {Microwaveprop.TaskSupervisor, self()}}`.
Concurrent work — the hourly PropagationGridWorker pulling f00-f18
HRRR range downloads, the GEFS worker scoring its grid, and the
Recalibrator's 20-way positive/negative fan-out — no longer funnels
through a single supervisor PID.
Light/one-shot Task.async + Task.start sites (hrrr_client surface/
pressure fan-out, application boot warmup, weather fire-and-forget)
are left alone; partitioning only helps under sustained concurrency.
Docker final stage bakes BUILD_TIMESTAMP into /app/BUILD_TIMESTAMP via
build-arg (only consumed after mix compile, so earlier layer caching is
preserved). Application.build_timestamp/0 reads the file, falls back to
DEPLOY_TIMESTAMP env, then to compile time. Navbar renders a compact
"Deployed Xm ago" with the full UTC time in the tooltip.
