fix: wrap app config in section cards, replace manual table with DataTable

- Add sectionStyles and tableStyles imports to AppsTab.tsx
- Wrap CreateAppView identity section and each config tab (Monitoring,
  Resources, Variables) in sectionStyles.section cards
- Wrap ConfigSubTab config tabs (Monitoring, Resources, Variables,
  Traces & Taps, Route Recording) in sectionStyles.section cards
- Replace manual <table> in OverviewSubTab with DataTable inside a
  tableStyles.tableSection card wrapper; pre-compute enriched row data
  via useMemo; handle muted non-selected-env rows via inline opacity
- Remove unused .table, .table th, .table td, .table tr:hover td, and
  .mutedRow CSS rules from AppsTab.module.css

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

ui/src/pages/AppsTab/AppsTab.module.css

@@ -119,38 +119,6 @@
   gap: 8px;
 }
 
-/* Table */
-.table {
-  width: 100%;
-  border-collapse: collapse;
-  margin-bottom: 16px;
-}
-
-.table th {
-  text-align: left;
-  padding: 8px 12px;
-  font-size: 11px;
-  font-weight: 600;
-  color: var(--text-muted);
-  text-transform: uppercase;
-  letter-spacing: 0.5px;
-  border-bottom: 1px solid var(--border-subtle);
-}
-
-.table td {
-  padding: 10px 12px;
-  border-bottom: 1px solid var(--border-subtle);
-  font-size: 13px;
-  vertical-align: middle;
-}
-
-.table tr:hover td {
-  background: var(--bg-hover);
-}
-
-.mutedRow td {
-  opacity: 0.45;
-}
 
 .mutedMono {
   font-family: var(--font-mono);