chore: sync annotation UI, shortcuts, and misc updates

backend/api/review.py

@@ -41,9 +41,11 @@ class AssistRequest(BaseModel):
 
 
 class PoolExemplar(BaseModel):
-    # Normalized xyxy against the frame, as drawn on the review canvas.
-    box: List[float]
+    # Normalized xyxy box or [x, y] point against the frame.
+    box: Optional[List[float]] = None
+    point: Optional[List[float]] = None
     positive: bool = True
+    kind: Optional[str] = None
 
 
 class ExemplarLabelRequest(BaseModel):