perf(ocr): raise image cap to 4096px for higher quality

perf(ocr): cap image at 2048px for dual-pass speed improvement

revert(ocr): restore dual-pass and 4096px, keep timing logs

perf(ocr): increase max image size to 2048px for better accuracy

perf(ocr): halve inference time on free CPU tier

feat: initial OCR server deploy