Add Toolchain page and bring the wiki up to v6.4.9
Document the in-OS C toolchain on a new Toolchain page: the userland libc,
the cc shell builtin, the TinyCC 0.9.27 port, and the tcc-compiles-tcc
self-host milestone (the in-OS tcc compiling its own ~40k-line source to a
valid x86-64 object).
Refresh the surrounding pages to match: Version-History through v6.4.9,
plus cross-links and content updates across the source-tree, userspace,
shell, filesystem, security and reference pages.
Wiki: escape pipes in table-cell [[Target|Display]] links (fixes broken nav links)
Aliased wiki-links inside markdown table cells collided with the table's own | column delimiter, so GitHub split the cell and rendered the link as literal '[[Target' text (Home 'Start here'/HOWTO/Subsystems/Reference tables, the Index page list, and a few reference pages). The pipe is now escaped as backslash-pipe, which both GitHub's wiki and Obsidian require inside a table cell; list-context links (the sidebar) were already fine and are untouched. 56 links across 8 pages.
Wiki update — v5.9.112, maintenance pass, new reference pages, source-tree reorg, full version history up to latest release
Wiki update - v5.9.88 animated GIFs, new HOWTO guides, glossary, FAQ, debugging, contributing
New pages: Contributing, Debugging, FAQ, Glossary, HOWTO-Add-a-GUI-application,
HOWTO-Add-a-shell-command, HOWTO-Add-a-system-call, HOWTO-Write-a-userspace-program,
Kernel-Data-Structures, Troubleshooting, Wiki-Conventions.
All existing pages updated through v5.9.88 (animated GIF playback, image decoders).
Wiki update for v5.9.87 - Selene browser, TLS, crypto arc, image decoders, desktop apps
New pages: Cryptography-and-TLS.md, Desktop-Applications.md,
Image-Decoders.md, Selene-Browser.md.
All existing pages updated to reflect v5.9.x changes (TLS 1.2, PNG/BMP/GIF
decoders, cooperative image loading, Selene tabs/forms/find, SMP locking,
the full visual arc).