fix(backfill): mark path enrichments :unavailable when pos2 is missing

Contacts lacking pos2 had terrain/radar/mechanism stuck on :pending, so
BackfillEnqueueWorker re-scanned them every cron cycle. Mark these
statuses :unavailable so the enqueue filter excludes them; a later pos2
edit resets them back to :pending via Radio.reset_enrichment_statuses/2.

lib/microwaveprop/workers/contact_weather_enqueue_worker.ex

@@ -97,9 +97,23 @@ defmodule Microwaveprop.Workers.ContactWeatherEnqueueWorker do
 
     if contact.pos1 && contact.pos2 do
       mark_path_statuses(contact, ids, types, jobs_by_type)
+    else
+      # Path enrichments (terrain/radar/mechanism) need both endpoints.
+      # Marking :unavailable stops BackfillEnqueueWorker from re-scanning
+      # these contacts every cron cycle. Radio.reset_enrichment_statuses/2
+      # will flip them back to :pending if pos2 is added later.
+      mark_missing_path_statuses(ids, types)
     end
   end
 
+  defp mark_missing_path_statuses(ids, types) do
+    if :terrain in types, do: Radio.set_enrichment_status!(ids, :terrain_status, :unavailable)
+    if :radar in types, do: Radio.set_enrichment_status!(ids, :radar_status, :unavailable)
+
+    if :mechanism in types,
+      do: Radio.set_enrichment_status!(ids, :propagation_mechanism_status, :unavailable)
+  end
+
   defp mark_pos1_statuses(contact, ids, types, jobs_by_type) do
     if :weather in types, do: mark_status!(ids, :weather_status, jobs_by_type[:weather])
     if :hrrr in types, do: mark_hrrr_status!(contact, ids, jobs_by_type[:hrrr])

test/microwaveprop/workers/contact_weather_enqueue_worker_test.exs

@@ -370,13 +370,13 @@ defmodule Microwaveprop.Workers.ContactWeatherEnqueueWorkerTest do
       assert updated.terrain_status == :queued
     end
 
-    test "skips terrain for QSOs missing pos2" do
-      _qso = create_contact(%{pos2: nil})
+    test "marks terrain :unavailable for QSOs missing pos2" do
+      contact = create_contact(%{pos2: nil, grid2: nil})
 
-      assert :ok = ContactWeatherEnqueueWorker.perform(%Oban.Job{args: %{}})
+      assert :ok = ContactWeatherEnqueueWorker.enqueue_for_contact(contact)
 
-      all_contacts = Repo.all(Contact)
-      refute Enum.any?(all_contacts, &(&1.terrain_status == :queued))
+      updated = Repo.get!(Contact, contact.id)
+      assert updated.terrain_status == :unavailable
     end
   end
 
@@ -682,7 +682,7 @@ defmodule Microwaveprop.Workers.ContactWeatherEnqueueWorkerTest do
       assert updated.iemre_status == :queued
     end
 
-    test "works for QSO without pos2 or grid2 (terrain stays pending)" do
+    test "works for QSO without pos2 or grid2 (path statuses flip to :unavailable)" do
       _station = create_asos_station("KDFW", 32.90, -97.04)
       contact = create_contact(%{pos2: nil, grid2: nil})
 
@@ -691,9 +691,12 @@ defmodule Microwaveprop.Workers.ContactWeatherEnqueueWorkerTest do
       updated = Repo.get!(Contact, contact.id)
       assert updated.weather_status == :queued
       assert updated.hrrr_status == :queued
-      # terrain requires pos2, so it can't be queued
-      assert updated.terrain_status == :pending
       assert updated.iemre_status == :queued
+      # Path-dependent enrichments need pos2 — marking :unavailable keeps
+      # BackfillEnqueueWorker from re-scanning these contacts every cron.
+      assert updated.terrain_status == :unavailable
+      assert updated.radar_status == :unavailable
+      assert updated.propagation_mechanism_status == :unavailable
     end
 
     # Pre-2014 contacts have no HRRR data ever; mark hrrr_status :unavailable