fix(runs): plain-language empty state with a guide button

The empty state explained itself in operator jargon (detach,
detached.enabled, operator config) and offered no way forward.
Now it says what background runs are in everyday language and
opens the built-in guide — which carries the exact activation
steps — via a real button. DE and EN.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/pages/runs.dart

@@ -127,6 +127,14 @@ class _RunsPageState extends State<RunsPage> {
               icon: Icons.rocket_launch_outlined,
               title: l.runsEmptyTitle,
               hint: l.runsEmptyHint,
+              // The guide carries the plain-language explanation plus
+              // the exact operator steps (config snippet) — a click
+              // target instead of a raw config key in the hint.
+              action: OutlinedButton.icon(
+                icon: const Icon(Icons.menu_book_outlined, size: 16),
+                label: Text(l.runsEmptyGuideButton),
+                onPressed: () => showFaiDoc(context, 'runs'),
+              ),
             )
           : ListView.separated(
               padding: const EdgeInsets.all(ChainSpace.lg),