fix(dashboard): scope h-full to xl + tighter mobile sizing on KPIs

The Alerts rail and Reminders rail were using h-full unconditionally, which
worked at xl: where the dashboard grid pairs them with a sibling chart
column, but produced weirdly stretched empty cards in the single-column
mobile stack (no fixed-height context to fill).

  alert-rail / my-reminders-rail: h-full -> xl:h-full

KPI tiles + skeleton rendered the same desktop padding (p-5) and font sizes
on phone, leaving the value cramped against a wide white frame. Tighter
mobile defaults that scale up at sm:

  KPITile      p-3 sm:p-5, label text-[10px] sm:text-xs,
               value mt-1 text-lg sm:mt-2 sm:text-2xl, value truncates
  KpiTileSkeleton: matching p-3 sm:p-5 + smaller skeleton bars on mobile

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

src/components/alerts/alert-rail.tsx

@@ -22,7 +22,11 @@ export function AlertRail() {
     <section
       data-testid="alert-rail"
       aria-label="Active alerts"
-      className="flex h-full flex-col gap-3"
+      // `h-full` is intentional only at xl: where the parent dashboard grid
+      // gives this rail a sibling column whose height it should match. On
+      // mobile (single-column stack) there's no fixed-height context, so
+      // forcing 100% height makes the section overflow / look stretched.
+      className="flex flex-col gap-3 xl:h-full"
     >
       <div className="flex items-baseline justify-between">
         <h2 className="text-sm font-semibold tracking-tight">Alerts</h2>

src/components/dashboard/kpi-cards.tsx

@@ -28,11 +28,10 @@ function formatPercent(value: number): string {
 
 function KpiTileSkeleton() {
   return (
-    <div className="relative overflow-hidden rounded-xl border border-border bg-card p-5 shadow-sm">
+    <div className="relative overflow-hidden rounded-xl border border-border bg-card p-3 shadow-sm sm:p-5">
       <div className="absolute inset-x-0 top-0 h-1 bg-muted" aria-hidden />
-      <Skeleton className="h-3 w-24" />
+      <Skeleton className="h-3 w-20" />
-      <Skeleton className="mt-3 h-7 w-32" />
+      <Skeleton className="mt-2 h-6 w-24 sm:mt-3 sm:h-7" />
-      <Skeleton className="mt-2 h-3 w-12" />
     </div>
   );
 }

src/components/dashboard/my-reminders-rail.tsx

@@ -67,8 +67,11 @@ export function MyRemindersRail() {
     return `/${portSlug}/reminders`;
   }
 
+  // `h-full` only at xl: where the dashboard grid pairs this rail with
+  // a sibling chart column. On mobile (stacked) it produced a weirdly
+  // tall empty card.
   return (
-    <Card className="h-full">
+    <Card className="xl:h-full">
       <CardHeader className="flex flex-row items-start justify-between gap-2 space-y-0 pb-3">
         <div className="space-y-0.5">
           <CardTitle className="flex items-center gap-1.5 text-base">

src/components/ui/kpi-tile.tsx

@@ -45,7 +45,7 @@ export function KPITile({
     <div
       data-testid="kpi-tile"
       className={cn(
-        'group relative overflow-hidden rounded-xl border border-border bg-gradient-brand-soft p-5 shadow-sm transition-all duration-base ease-smooth hover:shadow-md',
+        'group relative overflow-hidden rounded-xl border border-border bg-gradient-brand-soft p-3 shadow-sm transition-all duration-base ease-smooth hover:shadow-md sm:p-5',
         className,
       )}
       {...props}
@@ -53,10 +53,12 @@ export function KPITile({
       <div className={cn('absolute inset-x-0 top-0 h-1', ACCENT_STRIPES[accent])} aria-hidden />
       <div className="flex items-start justify-between gap-4">
         <div className="min-w-0">
-          <div className="text-xs font-medium uppercase tracking-wide text-muted-foreground">
+          <div className="text-[10px] font-medium uppercase tracking-wide text-muted-foreground sm:text-xs">
             {title}
           </div>
-          <div className="mt-2 text-2xl font-semibold tabular-nums text-foreground">{value}</div>
+          <div className="mt-1 truncate text-lg font-semibold tabular-nums text-foreground sm:mt-2 sm:text-2xl">
+            {value}
+          </div>
           {typeof delta === 'number' ? (
             <div className={cn('mt-1 text-xs font-medium', deltaClass)}>
               {deltaPrefix}