docs(web-ui): logs flyout fills side-panel height (follow-up to #543)

docs/web-ui.md

@@ -383,7 +383,10 @@ body sits to the right with three stacked lines
     fetches journald via `GET /api/journal/{name}?unit=&lines=`
     (`journalctl -M <container> -b --no-pager --output=short-iso`).
     A unit dropdown (harness service / full machine journal) and
-    a refresh button live in the panel.
+    a refresh button live in the panel. The panel uses a column-flex
+    layout so the `<pre>` log surface fills the full remaining panel
+    height (#541); scroll happens inside the `<pre>`, not the side
+    panel body.
   - Plain navigation links (config repo, forge profile,
     `dashboardLinks` extras) now live in the icon-only nav strip
     on Line 1 — see above (issue #262). The agent's `config` link