a11y: Select disabled (UI31), native colorScheme (UI32), touch targets (W16), High Contrast (W18)

UI31 — the native <Select> wrapper now takes a `disabled` prop that passes to
the <select> and applies disabled foreground/background/stroke tokens +
not-allowed cursor, so it can show a disabled state like Fluent controls.

UI32 — dropped the datetime-local's explicit colorScheme:'light dark' so it
inherits the resolved in-app scheme from the app root; the native calendar popup
now follows the app's Light/Dark theme, consistent with the native <Select>,
instead of tracking the OS preference.

W16 — the icon-only row-action clusters (QueueItem + HistoryView) enforce a
>=40x40px hit target via a `& button` min-size rule (glyph unchanged, subtle
button just gains padding). Labels were already non-hover-only: the shared Hint
shows on :focus-within and every action has an aria-label. LibraryView item rows
have no icon-only actions, so nothing there needed changing.

W18 — defended the two color-meaning surfaces against forced-colors: accent
swatches set forced-color-adjust:none (they're color previews; otherwise all
flatten to one system color), and the SegmentedControl active segment paints
with system Highlight/HighlightText under @media (forced-colors: active) so the
checked state stays visible. Status chips (Fluent Badge) and thumbnail tints
correctly let the system palette win.

typecheck + 253 tests + eslint + prettier + production build all green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CODE-AUDIT.md

@@ -971,10 +971,17 @@ are an undefined spacing/radius/type scale and a drift between Fluent components
 - [x] **UI30 — Hand-rolled radiogroups aren't arrow-navigable.** DownloadBar kind and Sidebar theme
   use `role="radiogroup"`/`radio` but implement click only — no ←/→ roving focus a radiogroup implies.
   **Standard:** roving-tabindex arrow keys, or Fluent's RadioGroup. *(a11y)*
-- [ ] **UI31 — `Select` can't be disabled.** The native-`<select>` wrapper exposes no `disabled` prop,
+- [x] **UI31 — `Select` can't be disabled.** The native-`<select>` wrapper exposes no `disabled` prop,
   so that control can't show a disabled state while Fluent controls can. **Standard:** add `disabled` + styling.
-- [ ] **UI32 — Native-control dark mode is uneven.** The DownloadBar `datetime-local` sets
+  *Fixed in [Select.tsx](src/renderer/src/components/Select.tsx): a `disabled` prop passes through to the
+  native `<select>` and applies a disabled style (disabled foreground/background/stroke tokens + `not-allowed`
+  cursor, hover suppressed) so it reads like a disabled Fluent control.*
+- [x] **UI32 — Native-control dark mode is uneven.** The DownloadBar `datetime-local` sets
   `colorScheme: 'light dark'` explicitly; the `Select` relies on the root `colorScheme`. **Standard:** set `colorScheme` consistently on both.
+  *Fixed in [downloadBar/styles.ts](src/renderer/src/components/downloadBar/styles.ts): dropped the explicit
+  `colorScheme: 'light dark'` on the `datetime-local` so it inherits the resolved in-app scheme set on the app
+  root (App.tsx) — the native calendar popup now follows the app's Light/Dark theme, consistent with the
+  native `<Select>`, rather than tracking the OS preference.*
 - [x] **UI33 — No semantic headings.** Titles render as `Subtitle2`/`Title2` (styled spans), so there's
   no h1–h6 hierarchy for screen-reader heading navigation (landmarks `<nav>`/`<main>` exist; headings
   don't). **Standard:** render titles as real headings (`as="h1"`/`"h2"` or `role="heading" aria-level`). *(a11y)*
@@ -1192,17 +1199,32 @@ DPI handled by Chromium). The deviations:
 - [ ] **W15 — Software rendering is global.** Hardware acceleration is disabled for a documented GPU
   workaround; on high-DPI/large windows this trades GPU compositing for CPU, which can be sluggish.
   **Standard:** re-enable HW accel where the target GPU allows (the memo already flags revisiting this).
-- [ ] **W16 — Touch targets too small / hover-only labels.** Icon-only row actions are ~32px, 4px apart,
+- [x] **W16 — Touch targets too small / hover-only labels.** Icon-only row actions are ~32px, 4px apart,
   4 per row (below the ~40px touch guideline), and their only labels are hover tooltips (`Hint`) that
-  never appear on touch. **Standard:** ≥40px touch targets and non-hover labels. *(extends UX17)*
+  never appear on touch. **Standard:** ≥40px touch targets and non-hover labels. *(extends UX17)* *Fixed:
+  the icon-only row-action clusters (QueueItem + HistoryView `actions` containers) now enforce a ≥40×40px
+  hit target via a `& button` min-size rule — the glyph is unchanged, the subtle button just carries more
+  padding. The label half was already covered: the shared [Hint](src/renderer/src/components/Hint.tsx) shows
+  on `:focus-within`, not only `:hover`, so keyboard/AT users get the name (and every action also has an
+  `aria-label`). (LibraryView's per-item rows have no icon-only actions — checkbox + status chip only; its
+  header actions are labeled text buttons — so nothing there needed enlarging.)*
 
 ### Dark mode & accessibility (Windows-specific)
 
 - [x] **W17 — No `aria-live` for status changes.** Narrator doesn't announce download progress,
   completion, or errors — there are no live regions. **Standard:** polite live regions for queue/status updates.
-- [ ] **W18 — Custom colors unverified under High Contrast.** The status pills, segmented controls, accent
+- [x] **W18 — Custom colors unverified under High Contrast.** The status pills, segmented controls, accent
   swatches, and thumbnail tints use explicit background colors that Windows forced-colors mode may not
   adapt (nothing sets `forced-color-adjust`). **Standard:** test under each Contrast theme; let system colors win.
+  *Fixed the two surfaces that convey meaning through color and would otherwise break under `forced-colors`:
+  the accent swatches ([settingsStyles.ts](src/renderer/src/components/settings/settingsStyles.ts)) now set
+  `forced-color-adjust: none` so the accents stay distinguishable (they're color previews — otherwise all
+  flatten to one system color), and the [SegmentedControl](src/renderer/src/components/ui/SegmentedControl.tsx)
+  active segment paints with the system `Highlight`/`HighlightText` pair under `@media (forced-colors: active)`
+  so the checked state stays visible once the brand background is flattened. The status chips are Fluent
+  `Badge`s (Fluent supplies its own forced-colors handling) and the thumbnail tints are purely decorative
+  placeholders, so both correctly let the system palette win. Live verification under each Contrast theme is
+  still worthwhile but the color-meaning surfaces are now defended in code.*
 - [ ] **(ref) No semantic headings / radiogroup arrow-nav / focus rings** — UI33, UI30, UI28–29 (all bear on Narrator + keyboard users).
 
 ### Settings & standard conventions (mostly OK)