docs(rock5): rotate ROCK 5T product images upright

[tzz-radxa]

Summary

• Rotate the ROCK 5T and ROCK 5T Industrial product-list images 180 degrees.
• Keep the existing image URLs, resolution and page markup unchanged, so the correction applies to both language versions of /rock5.

Why

The board lettering in both product-list images is upside down. The rotated images show the lettering upright.

Verification

• Decoded the before and after WebP files and confirmed the output pixels match an exact 180-degree rotation at the original dimensions (766x620 and 767x620).
• Ran pre-commit on both WebP files; all applicable hooks passed.
• Ran github_pr_guard.py check --fetch; one commit and two files in one static-asset scope.