Reduce cyclomatic complexity in multiple files

Extract helper functions to reduce cyclomatic complexity:

- telemetry/database_metrics.ex: Extract emit_packets_table_telemetry/7
  Moves multiple || 0 operators into separate function
  Reduces complexity from 10 to within limits

- packet_utils.ex: Extract build_weather_check_query/1
  Moves Ecto query building with multiple or conditions
  Reduces complexity from 11 to within limits

- packet.ex: Extract merge_extracted_data/3
  Moves telemetry and parser data merging logic
  Reduces complexity from 11 to within limits

Fixes 3 Credo cyclomatic complexity issues (7 remaining).

lib/aprsme/packet.ex

@@ -348,7 +348,12 @@ defmodule Aprsme.Packet do
           %{}
       end
 
-    # Also process telemetry fields from top-level attrs if not already processed
+    # Merge all extracted data
+    merge_extracted_data(base_attrs, additional_data, attrs)
+  end
+
+  defp merge_extracted_data(base_attrs, additional_data, attrs) do
+    # Process telemetry fields from top-level attrs if not already processed
     telemetry_data =
       if Map.has_key?(additional_data, :telemetry_vals) do
         # Already processed from data_extended

lib/aprsme/telemetry/database_metrics.ex

@@ -186,19 +186,7 @@ defmodule Aprsme.Telemetry.DatabaseMetrics do
            WHERE s.relname = 'packets'
          """) do
       {:ok, %{rows: [[live, dead, ins, upd, del, table_size, idx_size]]}} ->
-        :telemetry.execute(
-          [:aprsme, :postgres, :packets_table],
-          %{
-            live_tuples: live || 0,
-            dead_tuples: dead || 0,
-            total_inserts: ins || 0,
-            total_updates: upd || 0,
-            total_deletes: del || 0,
-            table_size_bytes: table_size || 0,
-            indexes_size_bytes: idx_size || 0
-          },
-          %{}
-        )
+        emit_packets_table_telemetry(live, dead, ins, upd, del, table_size, idx_size)
 
       _ ->
         :ok
@@ -251,4 +239,20 @@ defmodule Aprsme.Telemetry.DatabaseMetrics do
     # For now, we'll skip these as they require additional setup
     :ok
   end
+
+  defp emit_packets_table_telemetry(live, dead, ins, upd, del, table_size, idx_size) do
+    :telemetry.execute(
+      [:aprsme, :postgres, :packets_table],
+      %{
+        live_tuples: live || 0,
+        dead_tuples: dead || 0,
+        total_inserts: ins || 0,
+        total_updates: upd || 0,
+        total_deletes: del || 0,
+        table_size_bytes: table_size || 0,
+        indexes_size_bytes: idx_size || 0
+      },
+      %{}
+    )
+  end
 end

lib/aprsme_web/live/map_live/packet_utils.ex

@@ -62,20 +62,7 @@ defmodule AprsmeWeb.MapLive.PacketUtils do
   @spec has_weather_packets?(String.t()) :: boolean()
   # Get recent packets for this callsign and check if any are weather packets
   def has_weather_packets?(callsign) when is_binary(callsign) do
-    # Direct query without caching
-    import Ecto.Query
-
-    query =
-      from p in Aprsme.Packet,
-        where: p.sender == ^callsign,
-        where:
-          not is_nil(p.temperature) or not is_nil(p.humidity) or not is_nil(p.pressure) or
-            not is_nil(p.wind_direction) or not is_nil(p.wind_speed) or not is_nil(p.wind_gust) or
-            not is_nil(p.rain_1h) or not is_nil(p.rain_24h) or not is_nil(p.rain_midnight) or
-            not is_nil(p.luminosity) or not is_nil(p.snow_24h),
-        select: fragment("1"),
-        limit: 1
-
+    query = build_weather_check_query(callsign)
     Aprsme.Repo.exists?(query)
   rescue
     _ -> false
@@ -124,4 +111,18 @@ defmodule AprsmeWeb.MapLive.PacketUtils do
   defdelegate build_packet_data(packet), to: DataBuilder
 
   # All packet data building functions have been moved to AprsmeWeb.MapLive.DataBuilder
+
+  defp build_weather_check_query(callsign) do
+    import Ecto.Query
+
+    from p in Aprsme.Packet,
+      where: p.sender == ^callsign,
+      where:
+        not is_nil(p.temperature) or not is_nil(p.humidity) or not is_nil(p.pressure) or
+          not is_nil(p.wind_direction) or not is_nil(p.wind_speed) or not is_nil(p.wind_gust) or
+          not is_nil(p.rain_1h) or not is_nil(p.rain_24h) or not is_nil(p.rain_midnight) or
+          not is_nil(p.luminosity) or not is_nil(p.snow_24h),
+      select: fragment("1"),
+      limit: 1
+  end
 end