Bench falsified the v1 retransmit (testlogs/riomash-patched-62500-retx):
resends tracked NAKs 1:1 (321/321) yet lamps still stuck/missed — under
mash bursts the NAK arrives after a newer command is already "latest",
so the wrong packet was resent; and total shreds never NAK at all.
Now commands are stop-and-wait: ONE in flight (_commandGate), resolved
by ACK, NAK, or AckTimeout (50ms); NAK/timeout retransmits THE SAME
packet up to CommandRetransmitLimit (2), then drops (idempotent - the
next state update supersedes). Attribution is exact by construction and
timeouts catch silent shreds. Control-byte replies bypass the gate so
board traffic is never delayed; a request's own reply (analog/version/
check) also resolves the wait, so request/reply exchanges never burn
the timeout even if the board sends no explicit ACK.
7 tests (same-packet resend, timeout retry+drop, ACK completion,
serialization, reply-resolves-request, stray-NAK no-op, disable);
282 green. Mash summary now reports NAK/timeout resends.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Retargets RioJoy.Core/Overlay/Tray + tests from net8.0-windows to net48 so
the app can be tested as a framework-dependent build (relies on the in-box
.NET Framework 4.8 on Windows 10/11). Builds clean; all 241 tests pass.
Polyfills (no behavior change):
- PolySharp source generator for init/records/Index/Range/required members.
- System.Memory, System.Text.Json, Microsoft.Bcl.HashCode,
System.Threading.Channels (tests) NuGet packages.
- Compat/Net48Polyfills.cs: GetValueOrDefault, KeyValuePair.Deconstruct,
Math.Clamp; tests/TestPolyfills.cs: Task.WaitAsync.
Source adjustments for APIs absent on net48:
- ArgumentNullException/ArgumentException.ThrowIf* inlined to manual guards.
- Convert.ToHexString, Encoding.Latin1, Environment.ProcessPath,
ApplicationConfiguration.Initialize, Enum.GetNames<T>/GetValues<T>,
string.StartsWith(char), string.Split(char, opts), TextBox.PlaceholderText,
PeriodicTimer, Memory-based Stream Read/WriteAsync, array range-slicing.
- Dropped [SupportedOSPlatform] hints (net48 is single-platform).
deploy/build-package.ps1: publish framework-dependent (no self-contained).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>