Add VRS JSON format support for readsb integration

Added comprehensive support for VRS (Virtual Radar Server) JSON format
as a simpler alternative to Beast binary protocol, enabling integration
with readsb --net-vrs-port output.

## Key Features:
- **VRS JSON Parser**: Stream parsing of newline-delimited JSON aircraft data
- **VRS Client**: TCP client with automatic reconnection and error recovery
- **Mixed Format Support**: Use Beast and VRS sources simultaneously
- **Enhanced Aircraft Data**: Added VRS-specific fields (registration, type, operator)
- **Position Source Tracking**: Identifies ADS-B, MLAT, TIS-B, and satellite positions

## Implementation:
- `internal/vrs/parser.go`: VRS JSON message parsing and validation
- `internal/client/vrs.go`: VRS TCP client implementation
- Enhanced `MultiSourceClient` to support both Beast and VRS formats
- Extended `Aircraft` struct with validity flags and additional metadata
- Updated configuration to include `format` field ("beast" or "vrs")

## Testing:
- Successfully tested against svovel:33005 VRS JSON stream
- Verified aircraft data parsing and position tracking
- Confirmed mixed-format operation with existing Beast clients

## Documentation:
- Updated README.md with VRS format configuration examples
- Enhanced ARCHITECTURE.md with VRS parser documentation
- Added data format comparison and configuration guide

This enables simpler integration with modern readsb installations while
maintaining full backward compatibility with existing Beast deployments.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -1,12 +1,13 @@
 # SkyView - Multi-Source ADS-B Aircraft Tracker
 
-A high-performance, multi-source ADS-B aircraft tracking application that connects to multiple dump1090 Beast format TCP streams and provides a modern web interface with advanced visualization capabilities.
+A high-performance, multi-source ADS-B aircraft tracking application that connects to multiple dump1090/readsb receivers using Beast binary or VRS JSON formats and provides a modern web interface with advanced visualization capabilities.
 
 ## ✨ Features
 
 ### Multi-Source Data Fusion
-- **Beast Binary Format**: Native support for dump1090 Beast format (port 30005)
-- **Multiple Receivers**: Connect to unlimited dump1090 sources simultaneously
+- **Multiple Formats**: Support for both Beast binary (port 30005) and VRS JSON (port 33005) protocols
+- **Multiple Receivers**: Connect to unlimited dump1090/readsb sources simultaneously
+- **Mixed Sources**: Use Beast and VRS sources together in the same system
 - **Intelligent Merging**: Smart data fusion with signal strength-based source selection
 - **High-throughput Processing**: High-performance concurrent message processing
 
@@ -75,13 +76,25 @@ sudo systemctl enable skyview
   "sources": [
     {
       "id": "primary",
-      "name": "Primary Receiver",
+      "name": "Primary Receiver (Beast)",
       "host": "localhost",
       "port": 30005,
+      "format": "beast",
       "latitude": 51.4700,
       "longitude": -0.4600,
       "altitude": 50.0,
       "enabled": true
+    },
+    {
+      "id": "secondary",
+      "name": "Secondary Receiver (VRS JSON)",
+      "host": "192.168.1.100",
+      "port": 33005,
+      "format": "vrs",
+      "latitude": 51.4800,
+      "longitude": -0.4500,
+      "altitude": 75.0,
+      "enabled": true
     }
   ],
   "settings": {
@@ -97,6 +110,27 @@ sudo systemctl enable skyview
 }
 ```
 
+### Data Format Configuration
+
+SkyView supports two ADS-B data formats:
+
+#### Beast Binary Format
+- **Port**: Typically 30005
+- **Format**: Binary protocol developed by FlightAware
+- **Source**: dump1090, dump1090-fa, readsb with `--net-bo-port 30005`
+- **Configuration**: `"format": "beast"` (default if not specified)
+- **Advantages**: Compact binary format, includes precise timestamps and signal strength
+
+#### VRS JSON Format  
+- **Port**: Typically 33005
+- **Format**: JSON objects with aircraft arrays
+- **Source**: readsb with `--net-vrs-port 33005`
+- **Configuration**: `"format": "vrs"`
+- **Advantages**: Human-readable JSON, simpler to parse and debug
+- **Update Interval**: Configurable with `--net-vrs-interval` (default 5 seconds)
+
+Both formats can be used simultaneously in the same SkyView instance for maximum flexibility and redundancy.
+
 ### Command Line Options
 
 ```bash