deps: update Go and web dependencies

[jongio]

Routine dependency refresh.

Ecosystem	Package	From	To
Go	modernc.org/sqlite	1.58.0	1.59.0
Go	github.com/charmbracelet/ultraviolet	20260910	20260922
Go	github.com/charmbracelet/x/exp/golden	20260913	20260920
Go	github.com/charmbracelet/x/exp/slice	20260913	20260920
Go	github.com/dustin/go-humanize	1.0.1	1.1.0
Go	github.com/xo/terminfo	1.0.0	1.2.0
Go	modernc.org/libc	1.75.7	1.77.1
npm	astro	7.3.2	7.3.3
npm	marked	18.0.12	18.0.13
npm	@types/node	26.5.0	26.6.2

marked 18.0.14 is held back by the repository's 3-day release cooldown.

Validation: mage preflight, website typecheck/build/E2E tests, npm audit, and go mod verify pass.