style(settings): uniform vertical spacing across all sections

Pre-fix the per-card vertical rhythm was either `space-y-3` (AI
provider config forms), `space-y-5` (dashboard layout card) or
`space-y-4` (Account → Profile form). Three competing strides for
forms that visually live in the same shell, so the eye picks up the
discontinuity even though the section-level `space-y-6` outer rhythm
was already consistent.

Standardize on `space-y-4` between fields inside any single Settings
card:

- Dashboard "Customize layout" card: `space-y-5` -> `space-y-4`
- AI Codex / OpenAI / Anthropic / Local provider forms: `space-y-3` ->
  `space-y-4`

Account, Notifications and Export already used `space-y-4`. Section
roots and the AI parent card keep their `space-y-6` so distinct cards
still read as distinct surfaces.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/settings/integration-status-pill.tsx

@@ -110,7 +110,13 @@ export function IntegrationStatusPill({
     <Badge
       data-testid="integration-status-pill"
       data-state={state}
-      variant={state === "connected" ? undefined : state === "error" ? "destructive" : "outline"}
+      variant={
+        state === "connected"
+          ? undefined
+          : state === "error"
+            ? "destructive"
+            : "outline"
+      }
       aria-label={t("settings.integrationPill.ariaLabel")}
       className={cn(
         "max-w-full whitespace-nowrap",

src/components/settings/integrations-section.tsx

@@ -339,10 +339,7 @@ function WithingsCard({
           <Link2 className="text-primary h-5 w-5" />
           <h2 className="text-lg font-semibold">{t("settings.withings")}</h2>
         </div>
-        <IntegrationStatusPill
-          state={pillState}
-          lastSyncAt={pillLastSyncAt}
-        />
+        <IntegrationStatusPill state={pillState} lastSyncAt={pillLastSyncAt} />
       </div>
       <p className="text-muted-foreground mt-1 text-xs">
         {t("settings.withingsDescription")}