feat(llm): add Claude Opus 5, Sonnet 5, Kimi K3, and Qwen 3.8 models

[5wxwxwxw5]

Description

• Add newly released frontier models for Anthropic, Kimi, and DashScope Token Plan
• Complements the OpenAI GPT-5.6 changes tracked in providers: add newly released frontier models (Claude Opus 5, GPT-5.6, Kimi K3, Qwen 3.8) #632

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactoring (no functional changes)
• Documentation update
• CI / Build / Tooling

How Has This Been Tested?

• make test passes locally
• Manual testing (describe below)

Checklist

• My code follows the project's coding style (go fmt, go vet)
• I have performed a self-review of my code
• I have added tests that prove my fix is effective or my feature works
• New and existing unit tests pass locally with my changes
• I have updated the documentation accordingly (if applicable)
• I have signed the CLA

Related Issues

closes #632

[github-actions]

✅ OpenCodeReview: Review complete: 0 finding(s) across 1 selected item(s).

[lizhengfeng101]

LGTM