feat: add PCARS 1 & 2 UDP telemetry parser (port 5606)
- Auto-detect PCARS1 (1367-byte V1) vs PCARS2 (559-byte V2) packet format
- Parse speed, RPM, gear, inputs, tyres, engine temps, damage, weather
- Map PCARS-specific fields to TelemetryFrame (oil/water temp, damage, etc.)
- Add FeedSource::Pcars + 16 PCARS-specific Option fields to TelemetryFrame
- Port 5606 as optional bind-listen feed (like Telemetry Tool)
- 5 new unit tests for PCARS parser (32 total)
- Shared binary_utils module for all parsers