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

README.md

@@ -266,10 +266,10 @@ chicken-counter mortality --date 2026-05-23
 
 Key features:
 - **Multi-Image & Multi-Day Support**: Processes multiple images per day (e.g. morning/afternoon scans), aggregates the grand total carcass count (`total_mortality_count`), and saves outputs into date-isolated directories.
-- **2-Pass Detect & Refine**: runs the YOLO segmentation model once to find candidate regions, then uses `cv2.matchTemplate` to do a similarity search over each candidate before confirming it as a detection. This reduces false positives significantly.
+- **Direct High-Precision Segmentation (Default)**: Uses the **segmentation model** (`models/chicken-detection-model-v26n-seg-300e-best-2026-04-18.pt`) directly. 2-pass Detect & Refine (`two_pass: false`) is disabled by default because direct segmentation achieves higher accuracy and avoids false rejection on real farm photos.
+- **Optional 2-Pass Refine (`--two-pass`)**: An optional mode combining initial segmentation candidate proposals with `cv2.matchTemplate` similarity refinement.
 - **Containment filtering**: boxes where `IoA > 0.50` against a larger box are suppressed.
 - **Centroid deduplication**: detections whose centroids are within `dedupe_radius_px` of each other are merged to prevent counting the same carcass twice.
-- Uses the **segmentation model** (`models/chicken-detection-model-v26n-seg-300e-best-2026-04-18.pt`) which provides higher boundary precision than the standard detection model.
 
 Outputs for each daily run:
 - `output_<name>.jpg` — annotated images with bounding boxes and carcass IDs