chore(forest): sunset interests (2014–2023) → garden; redirect breadcrumbs
The 2014–2023 interest archive (uts-0166 index + entries uts-0030..0165) was
ported to the garden (utensil.github.io/garden/interests/). Delete those 137
trees from forest and repoint the two breadcrumb links (home uts-0169, learning
diary uts-0018) to the garden instead. Old per-entry forest URLs will 404;
content lives in the garden.