Suya OCR API — vLLM-backed, OpenAI-compatible OCR service

FastAPI service wrapping the Surya-OCR-2 model (datalab-to) served through vLLM:
legacy /v1/api/ai/* endpoints, an OpenAI-compatible /v1/chat/completions endpoint,
a coalescing request batcher, a local OCR CLI, Docker packaging, multilingual
example outputs, and quantization/concurrency benchmarks.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

surya/layout/schema.py

@@ -0,0 +1,19 @@
+from typing import List, Optional
+
+from pydantic import BaseModel
+
+from surya.common.polygon import PolygonBox
+
+
+class LayoutBox(PolygonBox):
+    label: str  # canonicalized via LAYOUT_PRED_RELABEL
+    raw_label: str  # original model label, before canonicalization
+    position: int  # reading order index
+    count: int = 0  # model's token estimate for OCR output (multiple of 50)
+
+
+class LayoutResult(BaseModel):
+    bboxes: List[LayoutBox]
+    image_bbox: List[float]
+    raw: Optional[str] = None  # raw model output, useful for debugging
+    error: bool = False