fix(ui): make exchange table fill page height with vertical scroll

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

@@ -1,23 +1,36 @@
-/* Scrollable content area */
+/* Scrollable content area — fills remaining height */
 .content {
+  display: flex;
+  flex-direction: column;
   flex: 1;
-  overflow-y: auto;
+  min-height: 0;
   min-width: 0;
   background: var(--bg-body);
 }
 
+/* Table section — stretches to fill and scrolls internally */
+
+
 /* Filter bar spacing */
 .filterBar {
   margin-bottom: 16px;
 }
 
-/* Table section */
 .tableSection {
+  display: flex;
+  flex-direction: column;
+  flex: 1;
+  min-height: 0;
   background: var(--bg-surface);
-  border-bottom: 1px solid var(--border-subtle);
   overflow: hidden;
 }
 
+.tableScroll {
+  flex: 1;
+  min-height: 0;
+  overflow-y: auto;
+}
+
 .tableHeader {
   display: flex;
   align-items: center;

ui/src/pages/Dashboard/Dashboard.tsx

@@ -267,27 +267,29 @@ export default function Dashboard() {
             </div>
           </div>
 
-          <DataTable
-            columns={columns}
-            data={rows}
-            onRowClick={handleRowClick}
-            selectedId={selectedId}
-            sortable
-            flush
-            onSortChange={handleSortChange}
-            rowAccent={handleRowAccent}
-            expandedContent={(row: Row) =>
-              row.errorMessage ? (
-                <div className={styles.inlineError}>
-                  <span className={styles.inlineErrorIcon}><AlertTriangle size={14} /></span>
-                  <div>
-                    <div className={styles.inlineErrorText}>{row.errorMessage}</div>
-                    <div className={styles.inlineErrorHint}>Click to view full stack trace</div>
+          <div className={styles.tableScroll}>
+            <DataTable
+              columns={columns}
+              data={rows}
+              onRowClick={handleRowClick}
+              selectedId={selectedId}
+              sortable
+              flush
+              onSortChange={handleSortChange}
+              rowAccent={handleRowAccent}
+              expandedContent={(row: Row) =>
+                row.errorMessage ? (
+                  <div className={styles.inlineError}>
+                    <span className={styles.inlineErrorIcon}><AlertTriangle size={14} /></span>
+                    <div>
+                      <div className={styles.inlineErrorText}>{row.errorMessage}</div>
+                      <div className={styles.inlineErrorHint}>Click to view full stack trace</div>
+                    </div>
                   </div>
-                </div>
-              ) : null
-            }
-          />
+                ) : null
+              }
+            />
+          </div>
         </div>
       </div>
     </>