v1.9.2: S3 right-click context menu — copy presigned download link

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/s3_client.py

@@ -277,6 +277,26 @@ class S3Client:
             log.error("S3 delete failed: %s", exc)
             return False
 
+    def generate_presigned_url(self, bucket: str, key: str,
+                               expires_in: int = 3600) -> str | None:
+        """Generate a presigned download URL for an object.
+
+        expires_in: URL lifetime in seconds (default 1 hour).
+        Returns URL string or None on failure.
+        """
+        if not self._ensure_connected():
+            return None
+        try:
+            url = self._client.generate_presigned_url(
+                "get_object",
+                Params={"Bucket": bucket, "Key": key},
+                ExpiresIn=expires_in,
+            )
+            return url
+        except Exception as exc:
+            log.error("S3 presigned URL failed: %s", exc)
+            return None
+
     def get_object_size(self, bucket: str, key: str) -> int:
         """Get size of an object in bytes."""
         if not self._ensure_connected():