fix: keep active sidebar label readable across themes

[LizAinslie]

Problem

Sidebar.astro marks the active item with menu-active bg-base-100. daisyUI's .menu-active sets color: var(--color-neutral-content), and the unlayered bg-base-100 utility only overrides the background. In themes where neutral-content and base-100 are both dark (or both light), the active label becomes unreadable — kolektiv-dark ≈1.11:1, nord ≈1.17:1, daisyUI Light ≈1.27:1.

Change

• Add text-base-content to the active class list so the pill keeps bg-base-100 with the guaranteed base-content foreground.
• Add an unlayered safety rule in src/styles/chrome.css: .menu a[aria-current='page'] { color: var(--color-base-content); }. It is scoped to aria-current, so SearchDialog hits (no aria-current) keep daisyUI's readable neutral/neutral-content pair.
• Comment the pairing so it is not "cleaned up" later.

Verification

Contrast (WCAG) of the active label, before → after:

Theme	Before	After
kolektiv-dark	1.11:1	17.61:1
nord	1.17:1	10.84:1
daisyUI Light	1.27:1	17.73:1
catppuccin-mocha	12.97:1	12.97:1

Playground built HTML active anchor class changed only by adding text-base-content. pnpm test (66 passed), pnpm typecheck, pnpm build and the playground build all pass.