Fix assembly bugs in EMS integration tests

[Copilot]

Three EMS integration tests were failing due to incorrect x86 assembly encoding in the test programs. The EMS implementation itself is correct.

Fixes

• Device name detection test: Missing DS segment setup and incorrect offset calculation

  • Added push cs; pop ds to set DS=CS before DOS file open call
  • Corrected device name offset from 0x20 to 0x1E (accounting for COM load address)

• Memory access tests: Missing ES segment override prefixes on write instructions

  • Added 0x26 prefix to mov byte [es:0], imm instructions (3 occurrences)
  • Adjusted conditional jump offsets to account for added bytes

Example

Before (writes to DS:0 instead of ES:0):

0xC6, 0x06, 0x00, 0x00, 0x42  // mov byte [0], 42h - uses DS by default

After (correctly writes to ES:0):

0x26, 0xC6, 0x06, 0x00, 0x00, 0x42  // mov byte [es:0], 42h - ES prefix

All 17 integration tests and 47 unit tests now pass.

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[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• av-build-tel-api-v1.avaloniaui.net
  • Triggering command: dotnet exec --runtimeconfig /home/REDACTED/.nuget/packages/avalonia.buildservices/11.3.1/tools/netstandard2.0/runtimeconfig.json /home/REDACTED/.nuget/packages/avalonia.buildservices/11.3.1/tools/netstandard2.0/Avalonia.BuildServices.Collector.dll (dns block)
  • Triggering command: dotnet test tests/Spice86.Tests/Spice86.Tests.csproj --filter FullyQualifiedName~EmsIntegrationTests --logger console;verbosity=detailed (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

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