Open a video's settings in a doc, paused at 0:09. Both sides are the same doc on Drop: before with comark-ui's main build, after with this PR's.

## comark-media: settings copy a link at the second, and the frame.

::compare{title="comark-media"}
:::screenshot{src="https://drop.vitehub.dev/f/3ef61c2d-4d54-4d08-89f9-5dd680e35267.png" alt="A video player's settings with Speed and Loop" viewport="420x230" href="https://drop.vitehub.dev/d/y7956fkegvs0/upload-flow-review"}
Settings hold the speed and looping.
:::

:::screenshot{src="https://drop.vitehub.dev/f/1345ead3-b208-438d-8783-b8e3dc12c885.png" alt="The same settings with Copy link at 0:09 and Copy frame under them" viewport="420x230" title="Proposed"}
::::annotation{x=12.2 y=50.5 w=7.1 h=23.7 mark="none" side="top" at=70 to="12.2,56.2"}
The file's own address with #t=9, read from the fallback link, so a host's blob: URL doesn't leak in.
::::

The label follows the time; Copy frame pauses and copies a PNG.
:::
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