feat: sync live-count, exemplar annotation modules, and update .gitignore

backend/api/review.py

@@ -40,6 +40,25 @@ class AssistRequest(BaseModel):
     threshold: float = 0.5
 
 
+class PoolExemplar(BaseModel):
+    # Normalized xyxy against the frame, as drawn on the review canvas.
+    box: List[float]
+    positive: bool = True
+
+
+class ExemplarLabelRequest(BaseModel):
+    # The whole frame-local pool, newest last (REQ-173/174).
+    exemplars: List[PoolExemplar]
+    class_id: int = 0
+    # The filter panel (REQ-175). Defaults mirror `exemplar.DEFAULTS`.
+    threshold: float = 0.5
+    iou_threshold: float = 0.8
+    min_box_frac: float = 0.002
+    max_detections: int = 100
+    # Off by default: a drag previews, only Apply writes.
+    apply: bool = False
+
+
 @router.get("/api/frames/{frame_id}/annotations")
 def list_annotations(frame_id: int) -> dict:
     target = review_store.frame(frame_id)
@@ -99,6 +118,24 @@ def assist(frame_id: int, request: AssistRequest) -> dict:
         raise HTTPException(400, str(exc))
 
 
+@router.post("/api/frames/{frame_id}/exemplar-label")
+def exemplar_label(frame_id: int, request: ExemplarLabelRequest) -> dict:
+    from backend import exemplar as exemplar_store
+
+    try:
+        return exemplar_store.label(
+            frame_id, request.class_id,
+            [item.model_dump() for item in request.exemplars],
+            threshold=request.threshold,
+            iou_threshold=request.iou_threshold,
+            min_box_frac=request.min_box_frac,
+            max_detections=request.max_detections,
+            apply=request.apply,
+        )
+    except review_store.ReviewError as exc:
+        raise HTTPException(400, str(exc))
+
+
 @router.post("/api/frames/{frame_id}/status")
 def set_status(frame_id: int, request: StatusRequest) -> dict:
     try: