feat: Cmd+K Enter applies full-text search to dashboard

When pressing Enter in the command palette without explicitly selecting
a result (via arrow keys or mouse), the search query is now applied as
a server-side full-text filter on the Dashboard table. Explicit
selection still navigates to the exchange. Updates design system to
v0.1.18 for the new onSubmit prop.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/Dashboard/Dashboard.module.css

@@ -30,11 +30,34 @@
 }
 
 .tableTitle {
+  display: flex;
+  align-items: center;
+  gap: 4px;
   font-size: 13px;
   font-weight: 600;
   color: var(--text-primary);
 }
 
+.clearSearch {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 18px;
+  height: 18px;
+  margin-left: 4px;
+  border: none;
+  background: var(--bg-hover, #F5F0EA);
+  color: var(--text-secondary, #5C5347);
+  border-radius: 50%;
+  cursor: pointer;
+  padding: 0;
+}
+
+.clearSearch:hover {
+  background: var(--border, #E4DFD8);
+  color: var(--text-primary, #1A1612);
+}
+
 .tableRight {
   display: flex;
   align-items: center;