Release 0.1.1: Converge provider capabilities

[egumaru]

Summary

• Finalizes the AIKernel.Providers 0.1.1 provider surface.
• Aligns provider categories across source, tests, solution folders, documentation, and Python native loading.
• Moves ChatOpenAIProvider into the Chat category to match its provider role.
• Keeps LLM, Compute, Pipeline, Standard, and Chat providers consistently organized.

Validation

• Release build passed with package generation disabled.
• .NET provider tests passed.
• Python wrapper tests passed.