fix: resolve all credo warnings and pre-existing dialyzer errors

- Move require Logger to module top level in SpatialPubSub
- Replace weak is_list assertions with stronger checks
- Remove redundant 'is a list' test in PromEx tests
- Replace apply/3 with direct function call in packet_replay test
- Fix unmatched_return in weather_cache.ex and callsign_view.ex

lib/aprsme/spatial_pubsub.ex

@@ -5,6 +5,8 @@ defmodule Aprsme.SpatialPubSub do
   """
   use GenServer
 
+  require Logger
+
   # Grid size in degrees for spatial indexing
   @grid_size 1.0
   # Maximum number of concurrent clients
@@ -252,7 +254,6 @@ defmodule Aprsme.SpatialPubSub do
   end
 
   defp normalize_bounds(invalid) do
-    require Logger
     Logger.warning("normalize_bounds called with invalid bounds map: #{inspect(invalid)}")
     %{north: 0.0, south: 0.0, east: 0.0, west: 0.0}
   end

lib/aprsme/weather_cache.ex

@@ -14,15 +14,16 @@ defmodule Aprsme.WeatherCache do
   The table is typically created in application.ex alongside other ETS tables.
   """
   def setup do
-    if :ets.whereis(@cache_name) == :undefined do
-      :ets.new(@cache_name, [
-        :named_table,
-        :public,
-        :set,
-        read_concurrency: true,
-        write_concurrency: true
-      ])
-    end
+    _table =
+      if :ets.whereis(@cache_name) == :undefined do
+        :ets.new(@cache_name, [
+          :named_table,
+          :public,
+          :set,
+          read_concurrency: true,
+          write_concurrency: true
+        ])
+      end
 
     :ok
   rescue

lib/aprsme_web/live/packets_live/callsign_view.ex

@@ -25,9 +25,10 @@ defmodule AprsmeWeb.PacketsLive.CallsignView do
   end
 
   defp subscribe_if_connected(socket, callsign) do
-    if connected?(socket) do
-      Phoenix.PubSub.subscribe(Aprsme.PubSub, "packets:#{callsign}")
-    end
+    _ =
+      if connected?(socket) do
+        Phoenix.PubSub.subscribe(Aprsme.PubSub, "packets:#{callsign}")
+      end
 
     socket
   end

test/aprsme/device_identification_test.exs

@@ -60,7 +60,6 @@ defmodule Aprsme.DeviceIdentificationTest do
   describe "known_manufacturers/0" do
     test "returns list of known manufacturers" do
       manufacturers = DeviceIdentification.known_manufacturers()
-      assert is_list(manufacturers)
       assert "Kenwood" in manufacturers
       assert "Yaesu" in manufacturers
       assert "Byonics" in manufacturers

test/aprsme/packet_replay_test.exs

@@ -58,7 +58,7 @@ defmodule Aprsme.PacketReplayTest do
       user_id = "test_user"
 
       assert_raise FunctionClauseError, fn ->
-        apply(PacketReplay, :update_filters, [user_id, %{callsign: "N0CALL"}])
+        PacketReplay.update_filters(user_id, %{callsign: "N0CALL"})
       end
     end
   end

test/aprsme/prom_ex_test.exs

@@ -8,10 +8,6 @@ defmodule Aprsme.PromExTest do
       {:ok, plugins: Aprsme.PromEx.plugins()}
     end
 
-    test "is a list", %{plugins: plugins} do
-      assert is_list(plugins)
-    end
-
     test "includes the built-in PromEx plugins", %{plugins: plugins} do
       modules = plugin_modules(plugins)
 

test/aprsme_web/telemetry_test.exs

@@ -6,7 +6,7 @@ defmodule AprsmeWeb.TelemetryTest do
   describe "metrics/0" do
     test "returns a non-empty list of metric definitions" do
       metrics = Telemetry.metrics()
-      assert is_list(metrics)
+      refute Enum.empty?(metrics)
     end
 
     test "includes Phoenix endpoint, router, and live_view metrics" do