Build comprehensive v4 wiki 11 pages: Home, Getting-Started, Configuration-Reference, Themes, Callbacks-and-MathJax, Tag-Based-Encryption, Migration-v3-to-v4, Security-Model, Browser-Support, FAQ, Troubleshooting. Plus _Sidebar for navigation. All internal cross-links resolve. All external links to the live demo + repo + npm verified. Source-of-truth for defaults/config is src/server/config.js#DEFAULTS. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot committed May 3, 2026