Document the runs screen, the run context and the generated dashboard

docs/getting-started/data-science.md

@@ -485,6 +485,21 @@ curl -s "$FLUKSIO/runs/series/compare?ids=$A,$B,$C&metric=train.loss" \
 
 which answers in exactly the shape a chart widget draws.
 
+## Looking at them in the portal
+
+None of the above needs a browser, but there is one. **Runs** is the table of
+everything that has run: filter it to a flow, to a status, or to one sweep —
+where it grows a column per parameter that actually varied — and tick two runs
+to put their curves side by side.
+
+A run records its metrics under the same names a dashboard binds to, so a
+dashboard is another way of reading one. **Open in dashboard** carries the
+runs you picked along in the URL, and every widget then answers for those runs
+instead of for the live engine. If the flow has no dashboard yet, the same
+menu builds one from the ports the flow declares.
+
+See [Runs → Looking at what ran](../concepts/runs.md#looking-at-what-ran).
+
 ## What sync does, at the API level
 
 Nothing here is privileged: `sync` is a client, and a flow is a document you