fix(workouts): show distance, pace and elevation in the reader's units

The workout list, the detail header, the stat tiles, the sport-average
line and the elevation chart printed kilometres, minutes per kilometre
and metres for every reader. They now read distance, pace and elevation
through the unit registry (km or mi, /km or /mi, m or ft). The splits
table keeps its kilometre rows, which are cut server-side, and says so.
A pace that rounded to sixty seconds now carries into the minute.

Refs #1067

src/lib/measurements/__tests__/display-transform.test.ts

@@ -384,7 +384,7 @@ describe("display-transform — both unit preferences, one resolver", () => {
     expect(mi.displayUnit).toBe("mi");
     expect(
       applyDisplayTransform(100, getQuantityTransform("elevation", "imperial")),
-    ).toBe(328);
+    ).toBe(328.1);
     expect(getQuantityTransform("elevation", "metric").displayUnit).toBe("m");
     // 30 min over 5 km: 360 s/km, 579.4 s/mi.
     expect(paceSecondsPerDistanceUnit(1800, 5000, "metric")).toBeCloseTo(

src/lib/measurements/display-transform.ts

@@ -260,8 +260,8 @@ const QUANTITY_TRANSFORMS: Record<
     imperial: { factor: 0.000621371192237, displayUnit: "mi", decimals: 2 },
   },
   elevation: {
-    metric: { factor: 1, displayUnit: "m", decimals: 0 },
-    imperial: { factor: M_TO_FT, displayUnit: "ft", decimals: 0 },
+    metric: { factor: 1, displayUnit: "m", decimals: 1 },
+    imperial: { factor: M_TO_FT, displayUnit: "ft", decimals: 1 },
   },
 };