UDP echo sample and benchmarks

[suleymanbyzt]

Sample projects and benchmarks for the UDP server and client, matching the existing TCP/WebSocket sample and benchmark structure.

Depends on #16 (StormUdpServer) and #17 (StormUdpClient).

Samples

Sample	Port	Description
StormSocket.Samples.UdpEcho	9000	UDP echo server, test with ncat -u localhost 9000

Benchmarks

Project	Description
StormSocket.Benchmark.UdpEchoServer	UDP echo benchmark server
StormSocket.Benchmark.UdpEchoClient	UDP echo benchmark client with configurable concurrency, message size, duration

Metrics to capture

• Throughput (MiB/s)
• Datagrams/sec
• Round-trip latency (ns)
• Comparison with NetCoreServer UDP echo

Run

# Sample
dotnet run --project samples/StormSocket.Samples.UdpEcho

# Benchmark
dotnet run -c Release --project benchmark/StormSocket.Benchmark.UdpEchoServer
dotnet run -c Release --project benchmark/StormSocket.Benchmark.UdpEchoClient -- -c 100 -m 1000 -s 32 -z 10