fix(weather-ca): drop the 1h freshness cutoff so HRDPS data renders

The 1-hour valid_time filter inherited from /weather is wrong for
HRDPS: the model publishes 4x/day with 3-4h publication latency and
the chain step adds ~13 min on top, so the freshest data on disk is
routinely 4-6h old. With the 1h cutoff in place, /weather-ca's
timeline was empty whenever there wasn't an active chain step running,
which left the JS hook with nothing to fetch. The sidebar already
shows the selected valid_time prominently — users can see for
themselves how stale the data is and don't need the page to hide it.

lib/microwaveprop_web/live/weather_ca_map_live.ex

@@ -104,13 +104,13 @@ defmodule MicrowavepropWeb.WeatherCaMapLive do
     Enum.min_by(valid_times, fn vt -> abs(DateTime.diff(vt, now, :second)) end)
   end
 
-  # Drop valid_times older than one hour. HRDPS cycles run 4×/day and
-  # the chain seeder writes one row per hour, so the on-disk set can
-  # span many old hours; the user wants "now", not yesterday.
-  defp recent_valid_times(valid_times) do
-    cutoff = DateTime.add(DateTime.utc_now(), -3600, :second)
-    Enum.filter(valid_times, fn vt -> DateTime.compare(vt, cutoff) != :lt end)
-  end
+  # Don't filter by recency. HRDPS publishes 4×/day with a 3-4h
+  # publication latency and our chain step adds ~13 min on top, so the
+  # freshest valid_time on disk is routinely 4-6h old. /weather's 1h
+  # cutoff would leave /weather-ca empty most of the time. The sidebar
+  # shows the selected valid_time in big letters — users can see for
+  # themselves how stale the data is.
+  defp recent_valid_times(valid_times), do: valid_times
 
   defp build_path(socket, overrides \\ []) do
     layer = Keyword.get(overrides, :layer, socket.assigns.selected_layer)

test/microwaveprop_web/live/weather_ca_map_live_test.exs

@@ -6,6 +6,7 @@ defmodule MicrowavepropWeb.WeatherCaMapLiveTest do
 
   alias Microwaveprop.Propagation.ProfilesFile
   alias Microwaveprop.Weather.GridCache
+  alias Microwaveprop.Weather.ScalarFile
 
   setup do
     GridCache.clear()
@@ -54,4 +55,35 @@ defmodule MicrowavepropWeb.WeatherCaMapLiveTest do
 
     assert_patch(lv, "/weather-ca?layer=pwat&lat=55.0&lon=-100.0&zoom=4")
   end
+
+  test "shows HRDPS valid_times even when several hours old (no 1h cutoff)", %{conn: conn} do
+    # HRDPS publishes 4x/day with ~3-4h latency, plus our chain step
+    # takes ~13 min. The 1-hour cutoff /weather uses would routinely
+    # leave /weather-ca empty between fresh chain steps. Hand-write a
+    # 4-hour-old HRDPS chunk and confirm it lands in the timeline.
+    now =
+      DateTime.utc_now()
+      |> DateTime.truncate(:second)
+      |> Map.put(:minute, 0)
+      |> Map.put(:second, 0)
+
+    stale_t = DateTime.add(now, -4 * 3600, :second)
+    hrdps_dir = ScalarFile.dir_for_hrdps(stale_t)
+    File.mkdir_p!(hrdps_dir)
+
+    payload =
+      Msgpax.pack!(
+        [%{"lat" => 53.0, "lon" => -60.0, "valid_time" => DateTime.to_iso8601(stale_t), "temperature" => 8.0}],
+        iodata: false
+      )
+
+    File.write!(Path.join(hrdps_dir, "10_-12.mp.gz"), :zlib.gzip(payload))
+
+    on_exit(fn -> File.rm_rf!(hrdps_dir) end)
+
+    {:ok, _lv, html} = live(conn, ~p"/weather-ca")
+
+    iso = DateTime.to_iso8601(stale_t)
+    assert html =~ iso, "4-hour-old HRDPS valid_time should appear in /weather-ca timeline"
+  end
 end