fix: Runtime tab respects selected environment

- Add environment parameter to AgentEventsController, AgentEventService,
  and ClickHouseAgentEventRepository (filters agent_events by environment)
- Wire selectedEnv to useAgents and useAgentEvents in both AgentHealth
  and AgentInstance pages
- Wire selectedEnv to useStatsTimeseries in AgentInstance

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

ui/src/api/queries/agents.ts

@@ -27,15 +27,16 @@ export function useAgents(status?: string, application?: string, environment?: s
   });
 }
 
-export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toOverride?: string) {
+export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toOverride?: string, environment?: string) {
   const refetchInterval = useRefreshInterval(15_000);
   return useQuery({
-    queryKey: ['agents', 'events', appId, agentId, limit, toOverride],
+    queryKey: ['agents', 'events', appId, agentId, limit, toOverride, environment],
     queryFn: async () => {
       const token = useAuthStore.getState().accessToken;
       const params = new URLSearchParams();
       if (appId) params.set('appId', appId);
       if (agentId) params.set('agentId', agentId);
+      if (environment) params.set('environment', environment);
       if (toOverride) params.set('to', toOverride);
       params.set('limit', String(limit));
       const res = await fetch(`${config.apiBaseUrl}/agents/events-log?${params}`, {