The APRS parser wasn't extracting altitude and PHG data from the comment
field. Added extraction functions to parse:
- Altitude from /A=XXXXXX format (converts to feet)
- PHG (Power-Height-Gain-Directivity) from PHGXXXX format
Also updated the comment cleaning to remove these technical details,
leaving only the human-readable station description.
Updated tests to properly use Packet.extract_additional_data() which
is where the parsing happens during packet processing.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
