revert: fit and polish promptwise's Timeline tab (#6) - #7

…ine and takes its chat's files (#8)

* Reapply "feat(studio): fit and polish promptwise's Timeline tab (#6)" (#7)

This reverts commit 16041d3.

* feat(studio): embedded in promptwise, the timeline looks like promptwise's own

On top of the reapplied tab fit (no second header, a compact dock):

- The timeline toolbar starts with history, the tool, split and zoom. Snapping,
  ripple, meters, keyframes, beats and the thumbnail and selection zooms open
  with More.
- Clips are flat blocks with no title band or shadow: the name is a small chip
  on pictures, and a text layer shows its words in the interface's type on the
  tertiary surface. Effect badges show on the clip in hand. Audio clips keep
  Studio's fill, which their waveform is drawn for.
- A panel alone in its group has no tab to name it.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

* feat(studio): promptwise's resize grip on the dock's dividers, and a play button that shows

- The dock's dividers no longer light up in the accent colour. Under the
  pointer or while dragged they show promptwise's sidebar grip, the white pill
  with three lines, turned on its side between the preview and the timeline.
- The play and pause glyph had a white fill, which vanished on the light
  surface. It is now promptwise's own Timeline's filled play and pause in the
  button's ink, and the button's hover is the toolbar's.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

* feat(studio): files dragged out of promptwise's chat land on the timeline

promptwise's chat drags its images, videos and sounds as a list of URLs under
its own type (application/x-bebra-asset). The timeline now takes that drop:
each file becomes a clip that plays from its own address, as the clips of a
converted promptwise timeline do, one after the other from the drop point.

A remote file's kind comes from its path, its length from loading its
metadata, and a video lands audible, since the project's probe can't reach it.
Its address is written as it is, with only the attribute's own characters
escaped. Anything that isn't an http(s) URL is ignored.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5.2 <noreply@anthropic.com>