2025.12.0

• [editor] Fix UI glitch where "select all" could unexpectedly cause all UI text to be selected instead of doing "select all" in the editor. PR 2332
• [font sources] Prompt the user with a warning when toggling the "Is sparse" source checkbox. Part of PR 2331.
• [kerning] Various kerning improvements (PR 2324):
  • Bring Fontra's kerning behavior in line with how fontmake treats designspace/ufo: every non-sparse source participates, falling back to zeros when values are missing
  • Fix a bug that allowed adding kerning to sparse sources
  • Improve "insert interpolated kerning source" so it will keep sparse kerning exceptions as sparse as possible
• [font overview] Distinguish more clearly between glyphs that exist and glyphs that do not exist in the font. Additionally, display the fallback glyph in existing but empty glyphs, both in the font overview and in the editor view. Issue 2311, PR 2313
• Prevent deletion or deactivation of last active glyph source. This prevents confusing behavior. Issue 2321, PR 2322
• Improve the "just start editing and the glyph source will come into existence" behavior for these cases (PR 2319):
  • Dragging the selection bounds handles to scale or rotate
  • Using various items in the Selection Transformation panel
• [font sources panel] Make source name list and source info panel scroll independently. Issue 2318
• Add "Is Sparse" checkbox to the font source UI. A "sparse" font source does not participate in kerning and in line metrics. (Part of the designspace PR mentioned below)
• In the sources panel, the default source name is now highlighted in bold. (Part of the designspace PR mentioned below)
• [designspace] Synchronize "sparse master" behavior with fontmake's behavior: if a <source> element has a layer attribute, consider the source "sparse". (Fontra's old behavior only considered sources sparse when the layer attribute was present and differed from the default layer name.) Issue 2314, PR 2315