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/NavSidebar.tsx

@@ -285,7 +285,7 @@ export default function NavSidebar({
                       key={a.id}
                       onClick={() => switchTo(a.id)}
                       title={t("header.account.switchTo", { name: a.display_name ?? a.email })}
-                      className="selectable w-full flex items-center gap-2.5 px-2 py-1.5 rounded-lg hover:bg-card transition"
+                      className="selectable w-full flex items-center gap-2.5 px-2 py-1.5 rounded-lg transition touch-target"
                     >
                       <AvatarImg
                         src={a.avatar_url}
@@ -311,14 +311,14 @@ export default function NavSidebar({
                     pinOnNextPage(null);
                     window.location.href = "/auth/login";
                   }}
-                  className="selectable w-full flex items-center gap-2 text-sm px-2 py-2 rounded-lg text-muted hover:text-fg hover:bg-card transition"
+                  className="selectable w-full flex items-center gap-2 text-sm px-2 py-2 rounded-lg text-muted hover:text-fg transition touch-target"
                 >
                   <UserPlus className="w-4 h-4" />
                   {t("header.account.addAccount")}
                 </Pressable>
                 <Pressable
                   onClick={logout}
-                  className="selectable w-full flex items-center gap-2 text-sm px-2 py-2 rounded-lg text-muted hover:text-fg hover:bg-card transition"
+                  className="selectable w-full flex items-center gap-2 text-sm px-2 py-2 rounded-lg text-muted hover:text-fg transition touch-target"
                 >
                   <LogOut className="w-4 h-4" />
                   {t("header.account.signOut")}