Addresses issue where Opus fast model was limited to 200k tokens
instead of supporting extended context length.
Changes:
- Add OPUS_FAST_CONFIGURATION.md with environment variable setup
- Add FAST_MODEL_CONFIG.md in migration plugin for fast deployment
- Update migration guide to include fast model strings and configuration
- Provide VSCode configuration options for fast model usage
The fast deployment supports >200k tokens and resolves the error:
"prompt is too long: 282789 tokens > 200000 maximum"
Configuration: Set ANTHROPIC_DEFAULT_OPUS_MODEL="claude-opus-4-5-20251101-fast"
