refactor duplicate cliplabels suffix error

Author: Copilot

poseinterface/clips.py

@@ -17,6 +17,10 @@
     BOTO3_AVAILABLE = False
 
 
+def _cliplabels_suffix_error(name: str) -> str:
+    return f"Input file must end with '_cliplabels.json', got {name}"
+
+
 def extract_clip(
     video_path: str | Path,
     start_frame: int,
@@ -218,10 +222,7 @@ def extract_start_frames_label(cliplabels_path: str | Path) -> Path:
 
     # Validate input filename
     if not cliplabels_path.name.endswith("_cliplabels.json"):
-        raise ValueError(
-            "Input file must end with '_cliplabels.json', "
-            f"got {cliplabels_path.name}"
-        )
+        raise ValueError(_cliplabels_suffix_error(cliplabels_path.name))
 
     # Read the cliplabels file
     with open(cliplabels_path) as f:
@@ -316,9 +317,7 @@ def extract_start_frames_label_s3(
 
     # Validate filename
     if not key.endswith("_cliplabels.json"):
-        raise ValueError(
-            f"Input file must end with '_cliplabels.json', got {key}"
-        )
+        raise ValueError(_cliplabels_suffix_error(key))
 
     # Initialize S3 client
     session = boto3.Session(profile_name=aws_profile)