fix: slope tooltip clipping — use clip:false + marginTop instead of dy function

site/src/components/ActivityCharts.svelte

@@ -355,15 +355,11 @@
     );
 
     if (isSlope) {
-      const nearTop = (d: any) => {
-        const range = lineDomainMax - lineDomainMin;
-        return range > 0 && (d[yKey] - lineDomainMin) / range > 0.85;
-      };
       marks.push(
         Plot.text(lineData, Plot.pointerX({
           x, y: yKey,
           text: (d: any) => d.slope != null ? `${d.slope > 0.05 ? '+' : ''}${(+d.slope).toFixed(1)}%` : '',
-          dy: (d: any) => nearTop(d) ? 22 : -22,
+          dy: -22, clip: false,
           fill: (d: any) => slopeColor(d.slope ?? 0),
           stroke: tc.tooltipBg, strokeWidth: 3,
           fontSize: 11, fontWeight: '700',
@@ -371,7 +367,7 @@
         Plot.text(lineData, Plot.pointerX({
           x, y: yKey,
           text: (d: any) => d[yKey] != null ? `${Math.round(d[yKey])}m` : '',
-          dy: (d: any) => nearTop(d) ? 10 : -10,
+          dy: -10, clip: false,
           fill: tc.axis, stroke: tc.tooltipBg, strokeWidth: 3,
           fontSize: 10,
         })),
@@ -397,7 +393,7 @@
         };
 
     const svg = Plot.plot({
-      width: w, height: h, marginLeft: 48, marginBottom: 32,
+      width: w, height: h, marginLeft: 48, marginBottom: 32, marginTop: isSlope ? 36 : 20,
       style: { background: 'transparent', color: tc.axis, fontSize: '11px' },
       x: { label: null, tickFormat: xTickFormat, grid: false, ticks: 6 },
       y: { label: yLabel, grid: true, tickCount: 4, domain: [lineDomainMin, lineDomainMax] },