Resolves the final 5 Credo cyclomatic complexity issues by:
1. packet.ex: Create get_field_value/2 helper function
- Replaces all `data[:field] || data["field"]` patterns
- Reduces complexity in put_equipment_fields (11 -> 9)
- Reduces complexity in put_phg_fields (12 -> 9)
- Reduces complexity in put_standard_parser_fields (11 -> 9)
2. query_builder.ex: Use SQL fragment for weather_only query
- Replaces multiple Elixir `or` operators with single SQL fragment
- Reduces complexity from 10 to within limits
3. packet_utils.ex: Use SQL fragment for weather check query
- Replaces multiple Elixir `or` operators with single SQL fragment
- Reduces complexity from 11 to within limits
All 71 Credo issues now resolved:
- 14/14 warnings ✓
- 14/14 design suggestions ✓
- 40/40 refactoring issues ✓
- 3/3 code readability issues ✓
100% Credo compliance achieved!
Graham McIntire
0eccbd2ac7