fix(custom-blocks): give a custom block's logo a tile its header chip can paint - #6929

Bugbot Analysis Progress (7m 42s elapsed)

✅ Gathered PR context (9s)
✅ Completed bug detection (7m 32s)
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Final Result: Bugbot completed review - no issues found! ✅

Request ID: serverGenReqId_ea10581f-1a2e-4d01-85fc-67109d237c64