Write a run's elapsed time once, in the duration formatter's units

The runs table drew when a run started and how long it took in two
notations ('56m ago | 55.5 min'), and for a run still going those are the
same reading twice. `dur` now steps past the minute into hours and days,
the ago reading is derived from it, and a running run writes only the
elapsed one.

frontend/src/components/Runs/RunsScreen.tsx

@@ -6,7 +6,6 @@ import { useRef } from "react"
 import type { fluksio__api__routes__runs__RunRow as RunRow } from "@/client"
 import { MAX_SERIES } from "@/components/Common/UplotChart"
 import { ValuePreview } from "@/components/Flow/ValuePreview"
-import { ago } from "@/components/Health/queries"
 import { Button } from "@/components/ui/button"
 import { Checkbox } from "@/components/ui/checkbox"
 import {
@@ -296,6 +295,12 @@ function ParamValue({ value }: { value: unknown }) {
   return <span className="font-mono text-xs">{paramText(value)}</span>
 }
 
+/** How long ago a moment was, in `dur`'s units so a row's two times agree. */
+function since(ts: unknown): string {
+  if (!ts) return "—"
+  return `${dur(Date.now() - Date.parse(String(ts)))} ago`
+}
+
 function RunsTable({
   runs,
   search,
@@ -456,14 +461,20 @@ function RunsTable({
                   only the store's, which is then the whole answer. */}
               {shortCommit(run.origin_commit || run.commit || "") || "—"}
             </TableCell>
-            <TableCell className="whitespace-nowrap text-muted-foreground text-sm">
+            <TableCell className="whitespace-nowrap text-muted-foreground text-sm tabular-nums">
               {/* When it started, and how long it then took. Two readings of
-                  one thing, so one column rather than two. */}
-              {ago(String(run.created_at ?? ""))}
+                  one thing, so one column rather than two — and while a run is
+                  still going they are the same reading, so it is written once:
+                  how long it has been running is also how long ago it began. */}
+              {run.status === "running" ? (
+                `${dur(run.duration_ms)} ago`
+              ) : (
+                <>
+                  {since(run.created_at)}
                   <span className="px-1.5 text-border">|</span>
-              <span className="tabular-nums">
-                {run.duration_ms ? dur(run.duration_ms) : "—"}
-              </span>
+                  <span>{run.duration_ms ? dur(run.duration_ms) : "—"}</span>
+                </>
+              )}
             </TableCell>
           </TableRow>
         ))}

frontend/src/lib/utils.check.ts

@@ -38,6 +38,8 @@ assert.equal(dur(0), "0 ms")
 assert.equal(dur(203.63), "204 ms")
 assert.equal(dur(1240), "1.24 s")
 assert.equal(dur(90_000), "1.5 min")
+assert.equal(dur(12_600_000), "3.5 h")
+assert.equal(dur(259_200_000), "3 d")
 
 // The plain window down to 0.01 ms, so a fast run keeps one unit across polls.
 assert.equal(dur(0.4), "0.4 ms")

frontend/src/lib/utils.ts

@@ -44,6 +44,8 @@ export function si(value: number, digits = 3): string {
 
 /** Floor, divisor and unit per step, largest first. */
 const DUR_STEPS: [number, number, string][] = [
+  [86_400_000, 86_400_000, "d"],
+  [3_600_000, 3_600_000, "h"],
   [60_000, 60_000, "min"],
   [1_000, 1_000, "s"],
   [0.01, 1, "ms"],
@@ -63,6 +65,9 @@ const DUR_STEPS: [number, number, string][] = [
  * window transposed onto units. That floor is deliberate: without it a tile
  * polled every ten seconds flips between "400 µs" and "1.2 ms", and a reading
  * that changes unit on every poll reads as broken rather than as fast.
+ *
+ * It keeps stepping past the minute into hours and days, so that an elapsed
+ * time is one notation wherever it is written — "3.5 h", never "210 min".
  */
 export function dur(ms: number, digits = 3): string {
   if (!Number.isFinite(ms)) return "--"