* feat: open documents dropped onto the window
Dropping a .fig, .pen, or other readable document did nothing: the canvas drop handler places only images and SVG files and swallowed everything else. The workspace now opens dropped documents in new tabs through the same path as File → Open, passing the file handle where the browser provides one, and reports files it cannot open instead of ignoring them. Images and SVG files dropped on the canvas are still placed.
* fix: classify each dropped file instead of matching File identities
DataTransferItem.getAsFile() may return a new File, so checking it against the canvas files from dataTransfer.files could miss images and SVG files and open them as documents in engines other than Chromium. Each extracted file is now classified on its own; a spec checks that an SVG dropped on the canvas is placed without opening a tab.
Replace internal references (Yoga, CanvasKit, Paragraph API, style runs,
characterStyleIDs, vectorNetworkBlob, Kiwi binary, scene graph, font-kit,
Local Font Access API, COMPONENT type, override key format, hex codes, px
specs) with user-facing language across all 7 locales.
Wrap all keyboard shortcut references in <kbd> tags in user guide,
reference, and development docs across all 7 locales (en, de, es,
fr, it, pl, ru). Tables, inline prose, and parenthetical hints.
