feat(lint): guard the gap-based Card slots against padding overrides

Add healthlog/spacing-scale (error): pt-*/pb-* on CardHeader/CardContent
fights the gap-based Card contract — the header→body distance comes from
the parent flex gap, so slot padding stacks on top of it or is a no-op.
This is the drift class the earlier slot-padding sweep cleaned; the rule
keeps it from reaccumulating. Density belongs on the Card itself
(gap-2 py-3 md:py-4). No allowlist — an exception, should one ever be
load-bearing, carries an inline disable with its reason.

Remove the two stragglers the rule caught: pb-1 on the device-score tile
and pb-4 md:pb-6 on the intake history list, both stacking dead padding
on top of the card gap. RuleTester coverage for the modifier-prefixed,
arbitrary-value, cn()/ternary/template and member-expression forms.

src/components/insights/device-score-tile.tsx

@@ -121,7 +121,7 @@ export function DeviceScoreTile({
           </CardAction>
         ) : null}
       </CardHeader>
-      <CardContent className="space-y-3 pb-1">
+      <CardContent className="space-y-3">
         {isLearning ? (
           <LearningGate
             compact

src/components/medications/intake-history-list-v2.tsx

@@ -238,7 +238,7 @@ export function IntakeHistoryListV2({
           {t("medications.intakeHistory")}
         </CardTitle>
       </CardHeader>
-      <CardContent className="pb-4 md:pb-6">
+      <CardContent>
         {isLoading ? (
           <div className="flex h-24 items-center justify-center">
             <Loader2 className="text-muted-foreground h-5 w-5 animate-spin motion-reduce:animate-none" />