A behaviour suite for the layers panel and the Assets panel written from the public documentation
(table rows with one-line derivations; rows the documentation is silent on say so and pin today's
behaviour), and the fixes it found.
- Engine suite `crates/engine/src/panels_behaviour_tests.rs` (6 tests, about 50 rows): reordering
and moving layers into frames, groups and auto layout, refused drops, renaming several layers,
show/hide and lock rules, pages and dividers, Assets folders, hidden-from-publishing names, drops.
- Panel suite `crates/ui-egui/src/layers_behaviour_tests.rs` (5 tests, driven through egui
headless): click / Shift range / Cmd-Ctrl toggle, Alt-click expand, Collapse layers, sweeping
across eyes and padlocks, the Rename layers dialog, dragging pages, dividers.
Fixes:
- Several layers dropped together in the layers panel land together at the drop point (layers
from apart split around it before).
- Collapse layers (Alt+L) keeps the rows leading to the selection open (it closed everything).
- The eye and padlock no longer vanish when the pointer reaches them (the row lost its hover to
them, so clicks could miss); dragging across eyes or padlocks sets every row passed in one undo
step. Layers inside a locked frame show a faint padlock.
- Several layers selected + Cmd/Ctrl+R / F2 / Rename open a Rename layers dialog (Match, Rename to,
Current name / Number up / Number down buttons, start value, preview) instead of renaming the top
row only.
- `object.batchRename`: `$n` counts up and `$N` down (they were swapped), `$nnn` pads, `start`
sets where numbers start/stop, `regex: true` matches a regular expression with `$1`..`$9`,
`` $` `` and `$'`, and codes work in the replacement too. Returns the new names.
- Pages: dragged up and down the list to reorder; a blank page named with a leading hyphen is a
divider (drawn as a line, never opened, holds no layers); duplicates are named "Copy of ...";
the last page that isn't a divider can't be deleted. `page.list` reports `divider`.
- Assets panel: components filed in folders by page, the frames holding them and the slash parts
of their names (folders fold away; open while searching), tiles show the last name part;
`component.list` gives each component's `folder` and `label` for agents.
- Publishing: a leading `.` or `_` keeps a component (style, collection) out of a library even
after it was published, and removing the prefix brings it back (the previous publish's choice
won before).
The engine gains the `regex` crate (already in the lock file through env_logger) for the
documented regular-expression matching.
