The ornamental design for a handheld steamcleaner, as shown and described.
FIG. 1 is a front, right and top perspective view of a handheld steam cleaner, showing my design.
FIG. 2 is a rear, left and bottom perspective view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a right side elevation view thereof.
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown in the drawings are included for the purpose of illustrating portions of the handheld steam cleaner that form no part of the claimed design.