feat(ui): add useInfiniteApplicationLogs hook

Server-side filters on source/level/time-range, client-side text
search on top of flattened items. Leaves useApplicationLogs and
useStartupLogs untouched for bounded consumers (LogTab, StartupLogPanel).

ui/src/api/queries/logs.ts

@@ -4,6 +4,7 @@ import { useAuthStore } from '../../auth/auth-store';
 import { useRefreshInterval } from './use-refresh-interval';
 import { useGlobalFilters } from '@cameleer/design-system';
 import { useEnvironmentStore } from '../environment-store';
+import { useInfiniteStream, type UseInfiniteStreamResult } from '../../hooks/useInfiniteStream';
 
 export interface LogEntryResponse {
   timestamp: string;
@@ -157,3 +158,79 @@ export function useStartupLogs(
     refetchInterval: isStarting ? 3_000 : false,
   });
 }
+
+export interface UseInfiniteApplicationLogsArgs {
+  application?: string;
+  agentId?: string;
+  sources?: string[];   // multi-select, server-side OR
+  levels?: string[];    // multi-select, server-side OR
+  exchangeId?: string;
+  isAtTop: boolean;
+  pageSize?: number;
+}
+
+/**
+ * Cursor-paginated log stream. Filters `sources`, `levels`, and the global
+ * time range are applied server-side. Free-text search is applied by the
+ * caller on top of the flattened items.
+ */
+export function useInfiniteApplicationLogs(
+  args: UseInfiniteApplicationLogsArgs,
+): UseInfiniteStreamResult<LogEntryResponse> {
+  const { timeRange } = useGlobalFilters();
+  const selectedEnv = useEnvironmentStore((s) => s.environment);
+
+  const useTimeRange = !args.exchangeId;
+  const fromIso = useTimeRange ? timeRange.start.toISOString() : undefined;
+  const toIso = useTimeRange ? timeRange.end.toISOString() : undefined;
+
+  const sortedSources = (args.sources ?? []).slice().sort();
+  const sortedLevels = (args.levels ?? []).slice().sort();
+  const sourcesParam = sortedSources.join(',');
+  const levelsParam = sortedLevels.join(',');
+  const pageSize = args.pageSize ?? 100;
+
+  return useInfiniteStream<LogEntryResponse>({
+    queryKey: [
+      'logs', 'infinite',
+      selectedEnv ?? '',
+      args.application ?? '',
+      args.agentId ?? '',
+      args.exchangeId ?? '',
+      sourcesParam,
+      levelsParam,
+      fromIso ?? '',
+      toIso ?? '',
+      pageSize,
+    ],
+    enabled: !!args.application && !!selectedEnv,
+    isAtTop: args.isAtTop,
+    fetchPage: async (cursor) => {
+      const token = useAuthStore.getState().accessToken;
+      const qp = new URLSearchParams();
+      if (args.application) qp.set('application', args.application);
+      if (args.agentId) qp.set('agentId', args.agentId);
+      if (args.exchangeId) qp.set('exchangeId', args.exchangeId);
+      if (sourcesParam) qp.set('source', sourcesParam);
+      if (levelsParam) qp.set('level', levelsParam);
+      if (fromIso) qp.set('from', fromIso);
+      if (toIso) qp.set('to', toIso);
+      if (cursor) qp.set('cursor', cursor);
+      qp.set('limit', String(pageSize));
+      qp.set('sort', 'desc');
+
+      const res = await fetch(
+        `${config.apiBaseUrl}/environments/${encodeURIComponent(selectedEnv ?? '')}/logs?${qp}`,
+        {
+          headers: {
+            Authorization: `Bearer ${token}`,
+            'X-Cameleer-Protocol-Version': '1',
+          },
+        },
+      );
+      if (!res.ok) throw new Error('Failed to load logs');
+      const page: LogSearchPageResponse = await res.json();
+      return { data: page.data, nextCursor: page.nextCursor, hasMore: page.hasMore };
+    },
+  });
+}