fix(storage): spacing between the enrichment tag row and action rows

The .drive-agent-extra slot stacked the agent tag row and the agent
action row with no vertical gap (and sat flush against the registry
action row). The slot is now a flex column with a .6rem gap + top
margin, hidden when empty; enrichCard's inline margin removed.

controller/internal/web/templates/style.css

@@ -3253,3 +3253,20 @@ span.mono, .mono { font-family: var(--font-data); }
 .nav-links-nested a.active {
     border-left: 3px solid var(--blue);
 }
+
+/* Unified drive view enrichment slot — breathing room between the agent tag row,
+   the agent action row, and the registry action row below. */
+.drive-agent-extra {
+    display: flex;
+    flex-direction: column;
+    gap: .6rem;
+    margin-top: .6rem;
+}
+.drive-agent-extra:empty { display: none; }
+.drive-agent-extra .metarows {
+    margin: 0;
+    gap: .3rem .75rem;
+}
+.drive-agent-extra .drive-actions {
+    margin: 0;
+}