PicToPC 0.6.4 - stable eBay insertion control

The Insert PicToPC photos button now floats at the bottom right. Options and progress open above it. The control lives outside eBay's application body and contributes no document height, so typing or photo-upload redraws do not repeatedly remove it and shift the listing. The same controls retain checkbox choices and transfer progress through redraws. Unrelated routes hide the control; browser history restoration reattaches observation.

No permission changes. The existing exact eBay host list, trusted-click requirement, document-bound transfers and field validation remain in place.

Verification: 42 host fixtures with 100 form redraws each, full body replacement during transfers, state preservation, duplicate prevention, route changes and existing protocol/uploader/field regression tests. A real Chrome local fixture also passed 100 redraws, retaining 2200px document height, scrollY 600 and unchanged button position, including opening/closing Options. Live eBay listing contents were not modified in testing.

After updating, reload PicToPC at chrome://extensions and refresh your eBay and PicToPC library tabs. Refreshing removes any older injected toolbar still running in an open page.
