fix: add unsaved changes banners to edit mode forms

Adds amber edit-mode banners to AppConfigDetailPage and both
DefaultResourcesSection/JarRetentionSection in EnvironmentsPage,
matching the existing ConfigSubTab pattern.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ui/src/pages/Routes/RouteDetail.tsx

@@ -6,6 +6,7 @@ import {
   Badge,
   StatusDot,
   DataTable,
+  EmptyState,
   Tabs,
   AreaChart,
   LineChart,
@@ -702,9 +703,7 @@ export default function RouteDetail() {
           {diagramFlows.length > 0 ? (
             <RouteFlow flows={diagramFlows} />
           ) : (
-            <div className={styles.emptyText}>
-              No diagram available for this route.
-            </div>
+            <EmptyState title="No diagram" description="No diagram available for this route." />
           )}
         </div>
         <div className={styles.statsPane}>
@@ -714,9 +713,7 @@ export default function RouteDetail() {
           ) : processorRows.length > 0 ? (
             <DataTable columns={processorColumns} data={processorRows} sortable pageSize={10} />
           ) : (
-            <div className={styles.emptyText}>
-              No processor data available.
-            </div>
+            <EmptyState title="No processor data" description="No processor data available." />
           )}
         </div>
       </div>
@@ -819,9 +816,7 @@ export default function RouteDetail() {
         {activeTab === 'errors' && (
           <div className={styles.errorPatterns} style={{ marginTop: 16 }}>
             {errorPatterns.length === 0 ? (
-              <div className={styles.emptyText}>
-                No error patterns found in the selected time range.
-              </div>
+              <EmptyState title="No error patterns" description="No error patterns found in the selected time range." />
             ) : (
               errorPatterns.map((ep, i) => (
                 <div key={i} className={styles.errorRow}>
@@ -841,9 +836,7 @@ export default function RouteDetail() {
               <Button variant="primary" size="sm" onClick={() => openTapModal(null)}>+ Add Tap</Button>
             </div>
             {routeTaps.length === 0 ? (
-              <div className={styles.emptyState}>
-                No taps configured for this route. Add a tap to extract business attributes from exchange data.
-              </div>
+              <EmptyState title="No taps" description="No taps configured for this route. Add a tap to extract business attributes from exchange data." />
             ) : (
               <DataTable
                 columns={tapColumns}