Fix/disasm: more inline evaluators (LDS, LES, LEA, CALL FAR)

[maximilien-noal]

Description of Changes

Fix gaps in the UI disasm expression evaluators for:

• LDS,
• LEA,
• LES,
• CALL FAR

Outside of LEA, changes are generic enough to fix more than those specific cases.

Before:

After:

Rationale behind Changes

Aid in reverse engineering

Suggested Testing Steps

Tested with manual tests. Covered by new UI integration tests which exercise the entire stack.

[Copilot]

Pull request overview

Improves the disassembly UI’s inline expression evaluation so that operand previews are correct for LEA (effective address vs. memory read) and for far-pointer memory operands used by LDS / CALL FAR.

Changes:

• Add special-case operand formatting for LEA to show computed effective address rather than dereferenced memory.
• Extend memory-size handling to support SegPtr16 (far pointers) as dword for evaluation/formatting.
• Add new Avalonia UI integration tests covering LEA, LDS, and CALL FAR evaluator behavior.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
tests/Spice86.Tests/UI/ExpressionEvaluatorUITests.cs	Adds UI integration tests for LEA, LDS, and CALL FAR operand evaluation/formatting.
src/Spice86/ViewModels/Services/ExpressionEvaluationService.cs	Updates operand evaluation logic to compute address expressions for LEA and handle far-pointer (SegPtr16) memory operands.

[maximilien-noal]

@copilot apply changes based on the comments in this thread

[Copilot]

@copilot apply changes based on the comments in this thread

Done in f9e334a:

• Removed unused Instruction instruction parameter from AddAddressValue and updated its call site
• Replaced all non-ASCII characters (→, —) with ASCII equivalents (->, -) throughout the test file
• Replaced all null-forgiving operator (!) usages with the evaluated ?? [] pattern after the existing NotBeNullOrEmpty() assertion (covers lines 83, 122, 155, 190, 228, 265, 302, 339)

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: /usr/share/dotnet/dotnet dotnet exec --runtimeconfig /home/REDACTED/.nuget/packages/avalonia.buildservices/11.3.2/tools/netstandard2.0/runtimeconfig.json /home/REDACTED/.nuget/packages/avalonia.buildservices/11.3.2/tools/netstandard2.0/Avalonia.BuildServices.Collector.dll (dns block)

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

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)