feat: add batch parallel image generation and provider-level throttling
- Add --batchfile and --jobs flags for multi-image parallel generation
with per-provider concurrency control and rate limiting
- Refactor main.ts into prepareSingleTask/prepareBatchTasks/runBatchTasks
with worker pool pattern and up to 3 retries per image
- Fix Replicate provider: use image_input array (nano-banana-pro schema),
add match_input_image aspect ratio, add quality-to-resolution mapping
- Improve OpenAI error message for missing API key (Codex auth hint)
- Expand non-retryable error detection (4xx codes, disabled models)
- Add batch config to EXTEND.md schema (max_workers, provider_limits)
- Add build-batch.ts for article-illustrator batch workflow integration
- Add image-language awareness pass to baoyu-translate
Co-authored-by: 敖氏 <aoshi@MacBook-Air.local>
5acef7151b