Fix Kimi tokenizer and CUDA payload loading

[yyj6666667]

What does this PR do?

• Use llguidance's native tiktoken support for Kimi tokenizers; other models keep the existing dispatch.
• Resolve lazy native binaries using their wheel-relative paths, preserving bundled library lookup. Legacy manifests remain supported.

Two production files, +24/-3 lines, with two focused test files. The packaging counterpart is kvcache-ai/ktransformers#2204.

Tests

• Focused tokenizer/payload tests: 6 passed in a fresh wheel-only environment.
• Original Kimi tokenizer: multilingual token IDs, EOS, vocabulary, and JSON grammar acceptance/rejection passed.
• Fresh native wheels: dependency / architecture audit and eight concurrent cold imports passed.
• Clean training/serving installation passed. Qwen two-GPU, Kimi four-GPU, and public FP8 GLM-5.3-Flash eight-GPU generation and JSON-schema checks passed.
• Kimi loaded both ordinary and expert LoRA from a freshly resumed training checkpoint; all converted tensors passed exact comparison. Full Neko style validation remains pending.

No model weights, attention kernels, or training runtime changes. Not a release sign-off.