fix(design): claim audit part 1b — whole-row switches, the field-family edge, state-layer hovers, icon links, reason-disabled controls, 24/44 targets (E28)

- F12 (owner: A): SwitchRow, the whole settings row toggles; a Config boolean toggles from its title
  and hint (a label pointed at the switch).
- F14 (owner: B): the form dropdown trigger wears the field frame (see-through, the >= 3:1 edge);
  labelled pills keep the faint edge and the accent-edge hover. DESIGN says so, with log rows.
- F6: ~15 bg-card / bg-border / opacity hovers onto the B3 state layer; a lint rule (HOVER_SWAP)
  refuses the swap, contract-tested.
- F10: bare 14px icon links onto IconLink / LinkButton; a local lint rule refuses a glyph-only <a>.
- F13: reason-disabled controls are aria-disabled (Users, Channels backfill, Discovery, Scheduler
  runs, Config tests); FocusSafeButton now swallows the click of a caller's aria-disabled; the
  Config tests say why while dirty (testDirty, HU/EN).
- F5/F11: every control measured live at 24 (mouse) and 44 (coarse) across every page; touch-target
  is a utility that wins over a caller's min-h-6; link variants carry it too; SegmentedToggle,
  Tabs, NavRail, menu rows, PriorityStepper, sliders, CheckRow, InnerInput, card links and the rest.
- F9: DismissibleChip's label reaches the chip's 24; the Combobox chips are DismissibleChips.
- F15: the "+N" / "More..." open state worded as it renders.

frontend/src/components/LanguageSwitcher.tsx

@@ -52,8 +52,8 @@ export default function LanguageSwitcher({
         layer
         className={
           rail
-            ? "relative p-2 rounded-lg text-muted hover:text-fg transition"
-            : "flex h-7 items-center gap-1.5 px-2.5 rounded-lg text-sm text-muted hover:text-fg transition"
+            ? "relative p-2 rounded-lg text-muted hover:text-fg transition touch-target"
+            : "flex h-7 items-center gap-1.5 px-2.5 rounded-lg text-sm text-muted hover:text-fg transition touch-target"
         }
       >
         <Globe className={rail ? "w-5 h-5" : "w-4 h-4"} />