fix: auto-compute environment slug + respect environment filter globally

Part A: Environment creation slug is now auto-derived from display name
and shown read-only (matching app creation pattern). Removes manual slug
input.

Part B: All data queries now pass the selected environment to backend:
- Exchanges search, Dashboard L1/L2/L3 stats, Routes metrics, Route
  detail, correlation chains, and processor metrics all filter by
  selected environment.
- Backend RouteMetricsController now accepts environment parameter for
  both route and processor metrics endpoints.

Closes #XYZ

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

ui/src/pages/Routes/RouteDetail.tsx

@@ -31,6 +31,7 @@ import { useDiagramByRoute } from '../../api/queries/diagrams';
 import { useProcessorMetrics } from '../../api/queries/processor-metrics';
 import { useStatsTimeseries, useSearchExecutions, useExecutionStats } from '../../api/queries/executions';
 import { useApplicationConfig, useUpdateApplicationConfig, useTestExpression } from '../../api/queries/commands';
+import { useEnvironmentStore } from '../../api/environment-store';
 import type { TapDefinition } from '../../api/queries/commands';
 import type { ExecutionSummary } from '../../api/types';
 import type { CatalogApp, CatalogRoute } from '../../api/queries/catalog';
@@ -272,6 +273,7 @@ function buildDetailKpiItems(
 export default function RouteDetail() {
   const { appId, routeId } = useParams();
   const navigate = useNavigate();
+  const selectedEnv = useEnvironmentStore((s) => s.environment);
   const { timeRange } = useGlobalFilters();
   const timeFrom = timeRange.start.toISOString();
   const timeTo = timeRange.end.toISOString();
@@ -305,16 +307,17 @@ export default function RouteDetail() {
   }, []);
 
   // ── API queries ────────────────────────────────────────────────────────────
-  const { data: catalog } = useCatalog();
+  const { data: catalog } = useCatalog(selectedEnv);
   const { data: diagram } = useDiagramByRoute(appId, routeId);
-  const { data: processorMetrics, isLoading: processorLoading } = useProcessorMetrics(routeId ?? null, appId);
-  const { data: stats } = useExecutionStats(timeFrom, timeTo, routeId, appId);
-  const { data: timeseries } = useStatsTimeseries(timeFrom, timeTo, routeId, appId);
+  const { data: processorMetrics, isLoading: processorLoading } = useProcessorMetrics(routeId ?? null, appId, selectedEnv);
+  const { data: stats } = useExecutionStats(timeFrom, timeTo, routeId, appId, selectedEnv);
+  const { data: timeseries } = useStatsTimeseries(timeFrom, timeTo, routeId, appId, selectedEnv);
   const { data: recentResult, isLoading: recentLoading } = useSearchExecutions({
     timeFrom,
     timeTo,
     routeId: routeId || undefined,
     applicationId: appId || undefined,
+    environment: selectedEnv,
     sortField: recentSortField,
     sortDir: recentSortDir,
     offset: 0,
@@ -325,6 +328,7 @@ export default function RouteDetail() {
     timeTo,
     routeId: routeId || undefined,
     applicationId: appId || undefined,
+    environment: selectedEnv,
     status: 'FAILED',
     offset: 0,
     limit: 200,