Add SURYA_STREAM_MODE streaming (off/on/abort) for chat completions

- _generate_one_stream: streams responses, optional live repeat-loop
  detection (abort) that closes the stream early and flags the partial
  result as repeat=True so the existing retry loop re-runs with higher
  temperature
- _should_retry honors result.repeat; stream_mode threaded through both
  first attempt and retry calls in chat_completions_batch
- GenerationResult.repeat field; SURYA_STREAM_MODE setting (default off)
- diagnostic retry logs (reason=repeat|error|detected, temp)
- docker-compose: SURYA_STREAM_MODE=off, 4090 GPU profile, logs volume
- logger.yaml: TimedRotatingFileHandler for error handler (fixes startup
  crash without maxBytes)

docker-compose.yml

@@ -5,12 +5,18 @@ services:
     runtime: nvidia
     environment:
       - VLLM_DTYPE=bfloat16
-      - VLLM_GPU_TYPE=a100
+      - VLLM_GPU_TYPE=4090
+      - VLLM_MAX_NUM_SEQS=32
+      - VLLM_MAX_BATCHED_TOKENS=8192
+      - SURYA_INFERENCE_MAX_INFLIGHT=32
+      # "off" | "on" | "abort" — streaming mode for chat completions
+      - SURYA_STREAM_MODE=off
       - NVIDIA_VISIBLE_DEVICES=all
     ports:
       - "5002:5002"
     volumes:
       - ~/.cache/huggingface:/root/.cache/huggingface
+      - ./logs:/opt/suya-ocr/logs
     deploy:
       resources:
         reservations: