Add mark capability audit
Migrate ROADMAP.md content to the wiki, split into Changelog/Backlog Migrated the repo root's ROADMAP.md content here in one step (combining what canvas_mojo's own wiki did as two separate moves): straight into Changelog (the former "Done" and "Removed" sections -- a build history, what was built, when, and why) and Backlog (the former "Explicitly still open" section -- what's deliberately not built yet, and why), rather than an intermediate single Roadmap page. Home.md links to both. Roadmap.md kept as a short pointer to the two new pages, mirroring canvas_mojo's own wiki (https://github.com/randyzwitch/canvas_mojo/wiki/Roadmap) for anyone who guesses the old name. Content verified preserved byte-for-byte (diffed the extracted section bodies against the original ROADMAP.md) except for each page's own new intro and a handful of now-cross-page "Done, above"/"Explicitly still open, below" references, fixed to name the other page explicitly.
Initial Home page