baseline prose: reflect the dataset-derived phase mix

The widget no longer rolls the last 5 minutes; it aggregates
time-weighted phase durations across a sampled slice of the
on-disk dataset. The prose now matches the bar.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

training/dashboard/static/index.html

@@ -419,12 +419,16 @@
         <div class="prose">
           <h2>A baseline of normal</h2>
           <p>Before we can detect a deviation, we have to know what the fleet
-            looks like when it's healthy. The stacked bar shows the fraction
-            of the last five minutes of fleet activity that sat in each phase
-            — a healthy mix has plenty of <code>clean</code>.</p>
+            looks like across a wide slice of its life. The stacked bar
+            aggregates ground-truth phase labels across hundreds of randomly
+            sampled episodes from the dataset on disk — weighted by the time
+            the workload actually spent in each phase, not just the count of
+            transitions.</p>
           <p>If the model only ever sees <code>clean</code>, it overfits to
-            "everything is fine." The phase schedule fixes that by forcing the
-            workload to walk through every phase on every run.</p>
+            "everything is fine." The phase schedule fixes that by forcing
+            every run to walk through every phase, which is why
+            <code>infected_running</code> dominates the mix — that's where
+            the labelled attack workload sits.</p>
         </div>
       </section>