ux: i18n leaks, focus rings, tap-target floor, admin chip-scroll, empty-state CTA vocabulary

Eight hotfix-ready UX/a11y findings from the v1.4.34.3 UX audit
land as one batch.

i18n leaks (3 primitives):
  - Dialog + Sheet close-X carried hardcoded `<span sr-only>Close</span>`
    so a German user heard 'Close, button' on every modal. Both lift
    `useTranslations()` and read `common.close`.
  - ChartSkeleton's sr-only loading announcement was English-only.
    The component is already a client island; reads `charts.loadingLabel`
    from each locale now. New key shipped in DE / EN / FR / ES / IT / PL.
  - Notifications-section breadcrumb `<nav aria-label="Breadcrumb">`
    was hardcoded. Routes through `t("nav.breadcrumb")` with a new
    key in each locale.

Focus rings (mobile + tablet nav):
  - Bottom-nav primary links + the More overflow trigger relied on a
    `text-muted-foreground` → `text-primary` colour transition only;
    keyboard / switch-control users saw no focus indicator at all.
    Added `focus-visible:ring-ring/50 focus-visible:ring-2
    focus-visible:outline-none focus-visible:ring-offset-2` matching
    the v1.4.33 sidebar treatment.
  - Mobile top-bar trigger had `focus:outline-none` without a
    `focus-visible` replacement. Same treatment applied.

Tap-target floor (WCAG 2.5.5):
  - Input / NativeSelect / Select / DateTimeInput were locked to
    h-10 (40 px) on every viewport. Switched to `h-11 sm:h-10` so
    mobile clears the 44 px floor while desktop keeps the 40 px norm
    that the Button primitive already converged on in v1.4.33.

Admin chip-strip auto-scroll-into-view:
  - The admin shell shipped 13 chips but lacked the
    `scrollIntoView({inline: 'center'})` effect the settings shell
    got in v1.4.33. Admins tapping a chip past the right edge landed
    on the new page with the strip scrolled to the left and the
    active chip off-screen. Copied the settings-shell pattern verbatim.

List-page subtitles on mobile:
  - Measurements / Mood / Medications pages hid their descriptive
    subtitle on `<sm` with `hidden sm:block`. Comparable apps keep
    the subtitle on mobile because it doubles as contextual help.
    Dropped the hide rule; the H1 still anchors the visual.

Insights empty-state CTA vocabulary:
  - `ALLOWED_ADD_TYPES` on `/measurements` accepted tokens (`GLUCOSE`,
    `TEMPERATURE`, `HEART_RATE`, `BMI`) that didn't match the
    `MEASUREMENT_TYPES` enum the form uses. Several `/insights/*`
    empty-state CTAs emitted those mismatched tokens and the dialog
    silently failed to open. Replaced with a single source of truth
    derived from `MEASUREMENT_TYPES` plus a normalisation map for
    legacy tokens. Added BODY_TEMPERATURE to the form's enum row.
    New unit test walks every `?add=` token emitted under
    `src/app/insights/**` and asserts it resolves to a real form type.

src/components/admin/admin-shell.tsx

@@ -156,6 +156,26 @@ export function AdminShell({ active, children }: AdminShellProps) {
   const { t } = useTranslations();
   const activeSlug = deriveActiveSlug(pathname, active);
 
+  // v1.4.34 IW-G — mirror the settings-shell auto-scroll pattern so
+  // the active chip stays in view when the user lands on a deeper
+  // admin route. Without it the 16-chip strip stays scrolled to the
+  // left and the active chip lives off-screen, reading as a broken nav.
+  const mobileStripRef = React.useRef<HTMLElement | null>(null);
+  React.useEffect(() => {
+    if (typeof window === "undefined") return;
+    const strip = mobileStripRef.current;
+    if (!strip) return;
+    const activeChip = strip.querySelector<HTMLElement>(
+      '[aria-current="page"]',
+    );
+    if (!activeChip) return;
+    activeChip.scrollIntoView({
+      block: "nearest",
+      inline: "center",
+      behavior: "smooth",
+    });
+  }, [activeSlug]);
+
   // v1.4.25 W8 — AuthShell wraps the page in `px-4 py-6 md:px-6`
   // already, so this inner shell only carries the wider max-width.
   // Previously the duplicate `px-4 py-6 md:px-6 md:py-8` here was
@@ -169,13 +189,19 @@ export function AdminShell({ active, children }: AdminShellProps) {
           horizontal swipe + keyboard arrow scrolling still work, the
           bar just doesn't draw. Without this the 13-section strip
           would render an always-on scrollbar that the maintainer kept
-          mis-attributing to the api-tokens table below it. */}
+          mis-attributing to the api-tokens table below it.
+
+          v1.4.34 IW-G — `snap-x snap-mandatory` plus per-chip
+          `snap-start` lets a swipe-flick land on the next chip's
+          leading edge instead of the in-between dead zone, matching
+          the settings-shell polish. */}
       <nav
+        ref={mobileStripRef}
         aria-label={t("admin.shell.sectionsNav")}
-        className="no-scrollbar -mx-4 mb-4 overflow-x-auto px-4 md:hidden"
+        className="no-scrollbar -mx-4 mb-4 snap-x snap-mandatory overflow-x-auto px-4 md:hidden"
       >
         <ul className="flex min-w-max gap-2">
-          <li>
+          <li className="snap-start">
             <Link
               href="/admin"
               aria-current={activeSlug === null ? "page" : undefined}
@@ -197,7 +223,7 @@ export function AdminShell({ active, children }: AdminShellProps) {
             const isActive = section.slug === activeSlug;
             const Icon = section.icon;
             return (
-              <li key={section.slug}>
+              <li key={section.slug} className="snap-start">
                 <Link
                   href={`/admin/${section.slug}`}
                   aria-current={isActive ? "page" : undefined}