[JFWooten4]

Summary

• Replace the static Pinkie Pie mirror artwork used by the Copy file URL toolbar button with the new transparent PNG depicting Pinkie and her reflection.
• Preserve the existing button semantics, markup, and sizing; only the PNG asset changes.
• Update CREDITS.md to acknowledge the original scene at 9:57 in the supplied YouTube video. The attribution documents provenance and does not imply licensing of the original show art.

Verification

• Verified the packaged image is a 128 × 128 PNG with transparency and fully transparent corners.
• Verified the committed PNG blob matches the generated asset byte-for-byte and the credits contain the timestamped source link.
• Compared the branch to main: 1 commit ahead, 0 behind; only src/assets/pinkie-mirror.png and CREDITS.md differ.
• Existing toolbar uses assets/pinkie-mirror.png at 25 × 25 px, so no behavior changes are needed.
• Full extension tests and visual review in Chrome/Brave have not been run locally; CI status is pending.