Unify card title size to text-sm

Several CardTitle usages were text-base while others were already
text-sm, giving section headers inconsistent sizes across pages.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BuWtppPBizG2NQRa31FCRa

components/stats/DeviceUsageTable.tsx

@@ -16,7 +16,7 @@ export function DeviceUsageTable({ devices }: { devices: DeviceUsageRow[] }) {
     return (
       <Card className="bp-glass">
         <CardHeader>
-          <CardTitle className="text-base">Device usage</CardTitle>
+          <CardTitle className="text-sm">Device usage</CardTitle>
         </CardHeader>
         <CardContent className="text-sm text-muted-foreground">No device activity yet.</CardContent>
       </Card>
@@ -26,7 +26,7 @@ export function DeviceUsageTable({ devices }: { devices: DeviceUsageRow[] }) {
   return (
     <Card className="bp-glass">
       <CardHeader>
-        <CardTitle className="text-base">Device usage</CardTitle>
+        <CardTitle className="text-sm">Device usage</CardTitle>
       </CardHeader>
       <CardContent>
         <Table>