The measured pair showed the shortened toast clearing the toolbar, but
only just. At 149 characters it rendered 114.5px tall, bottom edge at
y=126.5, against a hub filter row whose centre sits at y=127. Every
control hit-tested as clickable, so the check passed, by half a pixel.
A longer translation, a different font stack or a zoom level would have
put it back over the row and re-broken what #9293 reverted.

At 101 characters the toast ends near y=100 and does not reach the row
at all, so the result stops depending on sub-pixel layout. The budget in
the tests drops from 170 to 110, which now rejects the 149-char version
rather than accepting it.

The transport control is two clicks away in Model Hub and discoverable
without being told. A toast that eats the toolbar is not worth it.

…lbar (#9658)

* Reapply "Say why a Xet download sits at 0% until it finishes (#9159)" (#9293)

This reverts commit e326033.

* Shrink the Xet notice so it clears the hub toolbar

The notice itself was fine. Its size was not: 62 characters of title and
330 of description rendered 235px tall in the top-right corner, which is
where the Model hub keeps its own toolbar. While the toast was up the
capability filter, the sort dropdown, the Models and Datasets tabs and
the repo action icons sat underneath it. Hit testing each control's own
centre point put 4 to 6 of them inside the toast, so they could not be
clicked, three times per install at 8s each. That is what #9293 reverted.

Title is now 19 characters and the description 149, in plain language and
one paragraph, which drops the pre-line class the old blank line needed.
The character budget is asserted in the tests rather than left as a
convention, since the failure is invisible to unit tests and to a
screenshot taken at the wrong viewport.

* Drop the HTTP hint: it left a 0.5px margin, not a margin

The measured pair showed the shortened toast clearing the toolbar, but
only just. At 149 characters it rendered 114.5px tall, bottom edge at
y=126.5, against a hub filter row whose centre sits at y=127. Every
control hit-tested as clickable, so the check passed, by half a pixel.
A longer translation, a different font stack or a zoom level would have
put it back over the row and re-broken what #9293 reverted.

At 101 characters the toast ends near y=100 and does not reach the row
at all, so the result stops depending on sub-pixel layout. The budget in
the tests drops from 170 to 110, which now rejects the 149-char version
rather than accepting it.

The transport control is two clicks away in Model Hub and discoverable
without being told. A toast that eats the toolbar is not worth it.