Steps to reproduce:
1. Create a new project
2. Install com.cysharp.zstring via git URL: https://github.com/Cysharp/ZString.git?path=src/ZString.Unity/Assets/Scripts/ZString
3. Verify the project compiles successfully
4. Install com.unity.ai.assistant@1.6.0-pre.2 via Package Manager
5. Observe: ~100+ compilation errors appear, all CS0103: The name 'Unsafe' does not exist in the current context, originating from ZString source files (FormatHelper.cs, ZString.Concat.cs, DecimalEx.cs, BitOperations.cs, InternalSpanEx.cs, Shims.cs, StringBuilder.AppendJoin.cs, etc.)
6. Uninstall com.unity.ai.assistant -> observe no more compilation errors
Actual result: The AI Assistant's bundled System.Runtime.CompilerServices.Unsafe.dll hijacks the assembly identity, preventing auto-referenced assemblies from resolving the Unsafe type. This breaks any package that uses Unsafe without explicit precompiled references
Expected results: Installing com.unity.ai.assistant should not break compilation of other packages. The framework-provided System.Runtime.CompilerServices.Unsafe type should remain accessible to assemblies using auto-referencing)
Reproducible with: AI Assistant 1.6.0 - pre.2 (6000.0.68f1, 6000.3.8f1, 6000.4.0b9, 6000.5.0a1)
Not reproducible with: AI Assistant 1.6.0 - pre.2 (6000.5.0a2, 6000.5.0a7)
Fixed in: 6000.5.0a2
Environment tested: Windows 11 24H2