fix: show time labels on X-axis and tooltip for intra-day chart views

Added formatLabel prop to XAxis component. When viewing Today (hour
or minute interval), X-axis shows "2:00 PM" instead of "Mar 22".
Tooltip shows time for intra-day, date for multi-day.

components/dashboard/Chart.tsx

@@ -436,7 +436,13 @@ export default function Chart({
                   strokeWidth={2}
                   gradientToOpacity={0}
                 />
-                <VisxXAxis numTicks={6} />
+                <VisxXAxis
+                  numTicks={6}
+                  formatLabel={interval === 'minute' || interval === 'hour'
+                    ? (d) => d.toLocaleTimeString('en-US', { hour: 'numeric', minute: '2-digit' })
+                    : undefined
+                  }
+                />
                 <VisxYAxis
                   numTicks={6}
                   formatValue={(v) => {
@@ -445,14 +451,27 @@ export default function Chart({
                   }}
                 />
                 <VisxChartTooltip
-                  rows={(point) => {
+                  content={({ point }) => {
+                    const dateObj = point.dateObj as Date
                     const config = METRIC_CONFIGS.find((m) => m.key === metric)
                     const value = point[metric] as number
-                    return [{
-                      color: CHART_COLORS[metric],
-                      label: config?.label || metric,
-                      value: config ? config.format(value) : value,
-                    }]
+                    const title = interval === 'minute' || interval === 'hour'
+                      ? dateObj.toLocaleTimeString('en-US', { hour: 'numeric', minute: '2-digit' })
+                      : dateObj.toLocaleDateString('en-US', { weekday: 'short', month: 'short', day: 'numeric' })
+                    return (
+                      <div className="px-3 py-2.5">
+                        <div className="mb-2 font-medium text-neutral-400 text-xs">{title}</div>
+                        <div className="flex items-center justify-between gap-4">
+                          <div className="flex items-center gap-2">
+                            <span className="h-2.5 w-2.5 shrink-0 rounded-full" style={{ backgroundColor: CHART_COLORS[metric] }} />
+                            <span className="text-neutral-400 text-sm">{config?.label || metric}</span>
+                          </div>
+                          <span className="font-medium text-white text-sm tabular-nums">
+                            {config ? config.format(value) : value}
+                          </span>
+                        </div>
+                      </div>
+                    )
                   }}
                 />
               </VisxAreaChart>

components/ui/area-chart.tsx

@@ -1293,6 +1293,7 @@ Grid.displayName = "Grid";
 export interface XAxisProps {
   numTicks?: number;
   tickerHalfWidth?: number;
+  formatLabel?: (date: Date) => string;
 }
 
 interface XAxisLabelProps {
@@ -1346,7 +1347,7 @@ function XAxisLabel({
   );
 }
 
-export function XAxis({ numTicks = 5, tickerHalfWidth = 50 }: XAxisProps) {
+export function XAxis({ numTicks = 5, tickerHalfWidth = 50, formatLabel }: XAxisProps) {
   const { xScale, margin, tooltipData, containerRef } = useChart();
   const [mounted, setMounted] = useState(false);
 
@@ -1376,15 +1377,15 @@ export function XAxis({ numTicks = 5, tickerHalfWidth = 50 }: XAxisProps) {
       dates.push(new Date(time));
     }
 
+    const defaultFormat = (d: Date) => d.toLocaleDateString("en-US", { month: "short", day: "numeric" });
+    const fmt = formatLabel ?? defaultFormat;
+
     return dates.map((date) => ({
       date,
       x: (xScale(date) ?? 0) + margin.left,
-      label: date.toLocaleDateString("en-US", {
-        month: "short",
-        day: "numeric",
-      }),
+      label: fmt(date),
     }));
-  }, [xScale, margin.left, numTicks]);
+  }, [xScale, margin.left, numTicks, formatLabel]);
 
   const isHovering = tooltipData !== null;
   const crosshairX = tooltipData ? tooltipData.x + margin.left : null;