layerling 1.75.0

• French: The whole interface and the 16 chapters of the guide are in French, with the language list and the guide's language switch. It is picked automatically for a browser set to French. Made by @ZelTroN-2k3 with an AI assistant (pull request #368); a French reader is still welcome to go through it, wrong words are fixed with a small pull request.
• Arrow keys move by 0.01 mm when the snap grid is off: With the grid off an arrow key moved the selection by 0.1 mm. It now moves it by 0.01 mm, and Shift with an arrow by five times that. With a grid on, the arrows still follow the grid; for 0.1 mm steps choose the 0.1 mm grid. Suggested by @HopGabor62 (#370).
• The keys stand beside the names in a shape's settings, and Multicolor has one: Solid (S), Hole (H), Transparent (T) and Edit group (E) now show their keys in the settings card, and Multicolor, which had none, gets Shift+M: it switches the selected groups between each part in its own colour and one colour for the group, and it is in the shortcuts list. Shift+M used to turn on the mirror mode like M; M alone still does. Suggested by @prmod3d (#367).
• A custom snap grid can be offered whole only: Each custom snap grid in the workspace settings has a switch "Also half and quarter". With it off, the snap menu offers just the size you typed, not its half and quarter as well (so "10 mm" no longer adds a second 5.0 mm). It stays on for the grids you already have. Suggested by @rondlh (#329).
• A text with a line round its letters can be cut out again: With a block font the mesh of such a text could have small gaps along letters that touch, which the 3D kernel refused ("not manifold"), so grouping it as a hole with a plate stopped with "Could not cut this imported mesh cleanly". The 2D kernel now extrudes the text itself, and its mesh is closed. Reported by @Mycraftymama (#352).
• Extrude and Revolve stand side by side: In the Sketch tab the two ways to build a body from a sketch were in a drop-down under "Sketch to 3D". They are now two buttons next to each other in the Create group, each with its hint as tooltip and the question mark beside them, so switching between the modes takes one click less. Suggested by @prmod3d (#366).
• The sketch can show the parts seen through: The sketch showed a body only as its outline at the height of the sketch plane. A new button with layers in the view buttons on the left, "Show the parts seen through", draws all edges of the bodies on the sketch plane, thin and faint, whatever height they lie at, so you can trace round existing work; on an upright workplane set on a front face it is the front view of the part. Every edge that turns by more than 30 degrees, the outline of a body as seen from the plane and every open edge is drawn; a mesh with a great many is thinned to 30,000 pieces. The choice is kept in the browser. Asked for by @meecenz (#354).
• Video list: "10 things I love about Layerling and 3 things that Tinkercad does better" by TECHNOBENTO is now first in the list on the start page and in the guide.
• Center view reaches parts beyond the plate: A part lying beyond the edge of the plate could not be brought to the middle of the screen, because the view's pivot could not leave the plate. Center view now goes as far out as the selected part; the house button takes it back. Reported by @Mycraftymama (#352).
• The three start boxes share one ground: On the start page the box "Create new 3D design" had a cream ground, the two beside it white, and in the dark theme it was tinted orange. All three now have the same cream ground (in the dark theme the same dark one), and the icons of the two plain boxes no longer sit on a square of their own; the orange border and the solid orange icon still mark the first one.
• The icon tag takes PNG and JPG pictures: The icon tag window's Browse... now also takes a PNG or JPG file. The picture is traced into an outline, and the preview shows the outline; under it, Traced from chooses whether the Dark part or the Light part of the picture becomes the icon, at first the part that is not the background, the background being the part that takes up more of the picture's edge. Transparent pixels never belong to the icon. An SVG that holds nothing but one picture, as Inkscape saves an imported bitmap, is traced the same way instead of being refused; an SVG that only links to a picture outside it now says so in plain words. Another file... on the icon tag card takes pictures as well. The tracer is layerling's own: the outline runs between the pixels, specks are left out and the line is straightened to at most 1200 pieces, so the CAD kernel builds the layers quickly. Suggested by @plazmabokor in #359.
• PNG and JPG pictures in the import: The import window (and the start page's import) takes PNG and JPG files. A picture is traced into an outline, as for the icon tag, and comes in 50 mm wide with the picture's proportions, ready to be resized, in the editor as a sketch body like an SVG: the part of the picture that is not its background, the background being the part that takes up more of the picture's edge. An SVG that holds nothing but one picture is traced the same way instead of being refused, and the design keeps the traced outline as its SVG. An SVG that holds a picture next to a drawing says so. Suggested by @plazmabokor in #359.