docs: clarify that 2-pass mortality detection is disabled by default for higher accuracy

RUN.md

@@ -66,7 +66,7 @@ Put your model files in the `models/` directory.
 | :--- | :--- | :--- |
 | Batch video counting (TensorRT) | `models/chicken-detection-model-v26n-300e-best-2026-05-02-NEW.engine` | Maximum GPU throughput |
 | Base PyTorch weights | `models/chicken-detection-model-v26n-300e-best-2026-05-02-NEW.pt` | Used for portable runs and auto-recompiling engines |
-| Mortality detection | `models/chicken-detection-model-v26n-seg-300e-best-2026-04-18.pt` | 2-pass segmentation model |
+| Mortality detection | `models/chicken-detection-model-v26n-seg-300e-best-2026-04-18.pt` | Direct segmentation model (2-pass disabled by default for accuracy) |
 
 > **Self-Healing Recompilation on New Machines**: If you move the project to a new machine with a different GPU or OS, the pipeline will detect any incompatible `.engine`, automatically locate the matching `.pt` model, recompile a new `.engine` for the host machine, and update `configs/cycle7_batch_optimized.yaml` automatically.
 
@@ -149,7 +149,7 @@ A `mortality_report.json` is also saved there with full detection data.
 | `iou` | IoU NMS threshold |
 | `min_box_area_px` | Minimum bounding box area in pixels |
 | `dedupe_radius_px` | Centroid deduplication radius in pixels |
-| `two_pass` | Enable 2x Detect & Refine pipeline |
+| `two_pass` | 2x Detect & Refine pipeline (`false` by default; single-pass direct achieves higher accuracy on farm footage) |
 | `classes` | `[0]` = chicken only; ignores background/text/equipment |
 
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