Improve deploy errors and use bottom job tray as sole feedback.

Map Docker deploy failures to actionable how-to-fix messages, keep full
detail through RPC sanitization, and stop top-center toasts from doubling
the live job tray so operators only see one notification per action.

ui/ops.css

@@ -158,7 +158,16 @@
   padding: 0.35rem 0;
   font-size: 0.9rem;
 }
-.job-step-error { grid-column: 2; color: #f87171; font-size: 0.8rem; }
+.job-step-error {
+  grid-column: 2;
+  color: #f87171;
+  font-size: 0.8rem;
+  white-space: pre-wrap;
+  word-break: break-word;
+  line-height: 1.35;
+  max-height: 6rem;
+  overflow-y: auto;
+}
 .job-step-detail { grid-column: 2; font-size: 0.8rem; }
 .job-log-details { margin-top: 0.75rem; }
 .job-log-details > summary {
@@ -268,9 +277,9 @@
   position: fixed;
   right: 1rem;
   bottom: 1rem;
-  width: min(24rem, calc(100vw - 2rem));
+  width: min(28rem, calc(100vw - 2rem));
   z-index: 2500;
-  max-height: 50vh;
+  max-height: 60vh;
   overflow: auto;
   pointer-events: none;
   opacity: 0;