• fix width in zen mode, closes #1965
• don't error out when backend log does not exist yet, fixes #1977
• imported internal links crash ckeditor, #1979
• reorder database initialization so that all critical sections are in the same transaction, #1985
• reimplementation of ZIP export using archiver.js library #1938
• Update KaTeX to v0.13.9 (#1925)
• Add support for mhchem markup in KaTeX (#1917)