fix(mixed-timeseries): apply same axis formatting options as timeseries charts (#38979)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

superset-frontend/plugins/plugin-chart-echarts/src/MixedTimeseries/transformProps.ts

@@ -578,9 +578,31 @@ export default function transformProps(
       : String;
   const xAxisFormatter =
     xAxisDataType === GenericDataType.Temporal
-      ? getXAxisFormatter(xAxisTimeFormat)
+      ? getXAxisFormatter(xAxisTimeFormat, timeGrainSqla)
       : String;
 
+  const showMaxLabel = xAxisType === AxisType.Time && xAxisLabelRotation === 0;
+  const deduplicatedFormatter = showMaxLabel
+    ? (() => {
+        let lastLabel: string | undefined;
+        const wrapper = (value: number | string) => {
+          const label =
+            typeof xAxisFormatter === 'function'
+              ? (xAxisFormatter as Function)(value)
+              : String(value);
+          if (label === lastLabel) {
+            return '';
+          }
+          lastLabel = label;
+          return label;
+        };
+        if (typeof xAxisFormatter === 'function' && 'id' in xAxisFormatter) {
+          (wrapper as any).id = (xAxisFormatter as any).id;
+        }
+        return wrapper;
+      })()
+    : xAxisFormatter;
+
   const addYAxisTitleOffset =
     !!(yAxisTitle || yAxisTitleSecondary) &&
     convertInteger(yAxisTitleMargin) !== 0;
@@ -658,9 +680,14 @@ export default function transformProps(
       nameGap: convertInteger(xAxisTitleMargin),
       nameLocation: 'middle',
       axisLabel: {
-        formatter: xAxisFormatter,
+        hideOverlap: !(xAxisType === AxisType.Time && xAxisLabelRotation !== 0),
+        formatter: deduplicatedFormatter,
         rotate: xAxisLabelRotation,
         interval: xAxisLabelInterval,
+        ...(showMaxLabel && {
+          showMaxLabel: true,
+          alignMaxLabel: 'right',
+        }),
       },
       minorTick: { show: minorTicks },
       minInterval: