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/Stats.tsx

@@ -290,11 +290,13 @@ function SystemStats() {
                 {data.daily.map((d) => (
                   <div
                     key={d.day}
-                    className="flex-1 h-full flex items-end bg-card/50 rounded-t"
+                    // The day under the pointer is lit by the B3 layer over its whole column, not by
+                    // dimming the bar: an opacity dim reads as "disabled".
+                    className="flex-1 h-full flex items-end bg-card/50 rounded-t state-layer"
                     title={t("stats.dailyTooltip", { day: d.day, units: formatNumber(d.total) })}
                   >
                     <div
-                      className="w-full bg-accent hover:opacity-80 rounded-t transition"
+                      className="w-full bg-accent rounded-t"
                       style={{ height: `${Math.max(3, (d.total / maxDaily) * 100)}%` }}
                     />
                   </div>