[Logs Explorer] Fix Privileges Accessibility (elastic#193894)

closes elastic#192062

## 📝  Summary

This PR adds privileges checks for `Logs Explorerer` it checks for
`Discover & Fleet` privileges before allowing the user access to `Logs
Explorer`.
Clicking on the `Logs` tab from the side nav defaults to `Stream`, as
long as its not depricated, in case the user doesn't have access to
`Logs Explorer`

## 🎥 Demo

https://github.com/user-attachments/assets/a4105ec0-7681-40ee-b2fd-e39b9c178dcf
(cherry picked from commit dbfd4f0)

x-pack/plugins/observability_solution/infra/public/apps/logs_app.tsx

@@ -57,7 +57,7 @@ const LogsApp: React.FC<{
   storage: Storage;
   theme$: AppMountParameters['theme$'];
 }> = ({ core, history, pluginStart, plugins, setHeaderActionMenu, storage, theme$ }) => {
-  const uiCapabilities = core.application.capabilities;
+  const { logs, discover, fleet } = core.application.capabilities;
 
   return (
     <CoreProviders core={core} pluginStart={pluginStart} plugins={plugins} theme$={theme$}>
@@ -74,19 +74,21 @@ const LogsApp: React.FC<{
             toastsService={core.notifications.toasts}
           >
             <Routes>
-              <Route
-                path="/"
-                exact
-                render={() => {
-                  plugins.share.url.locators
-                    .get<AllDatasetsLocatorParams>(ALL_DATASETS_LOCATOR_ID)
-                    ?.navigate({});
+              {Boolean(discover?.show && fleet?.read) && (
+                <Route
+                  path="/"
+                  exact
+                  render={() => {
+                    plugins.share.url.locators
+                      .get<AllDatasetsLocatorParams>(ALL_DATASETS_LOCATOR_ID)
+                      ?.navigate({});
 
-                  return null;
-                }}
-              />
+                    return null;
+                  }}
+                />
+              )}
               <Route path="/link-to" component={LinkToLogsPage} />
-              {uiCapabilities?.logs?.show && <Route path="/" component={LogsPage} />}
+              {logs?.show && <Route path="/" component={LogsPage} />}
             </Routes>
           </KbnUrlStateStorageFromRouterProvider>
         </Router>

x-pack/plugins/observability_solution/infra/public/pages/logs/page_content.tsx

@@ -113,6 +113,7 @@ export const LogsPageContent: React.FunctionComponent = () => {
         )}
         <RedirectWithQueryParams from={'/analysis'} to={anomaliesTab.pathname} exact />
         <RedirectWithQueryParams from={'/log-rate'} to={anomaliesTab.pathname} exact />
+        <RedirectWithQueryParams from={'/'} to={streamTab.pathname} exact />
         <Route
           render={() => (
             <NotFoundPage

x-pack/plugins/observability_solution/infra/public/plugin.ts

@@ -137,19 +137,24 @@ export class Plugin implements InfraClientPluginClass {
             ],
             isInfrastructureHostsViewEnabled,
           ]) => {
+            const { infrastructure, logs, discover, fleet } = capabilities;
             return [
-              ...(capabilities.logs.show
+              ...(logs.show
                 ? [
                     {
                       label: 'Logs',
                       sortKey: 200,
                       entries: [
-                        {
-                          label: 'Explorer',
-                          app: 'observability-logs-explorer',
-                          path: '/',
-                          isBetaFeature: true,
-                        },
+                        ...(discover?.show && fleet?.read
+                          ? [
+                              {
+                                label: 'Explorer',
+                                app: 'observability-logs-explorer',
+                                path: '/',
+                                isBetaFeature: true,
+                              },
+                            ]
+                          : []),
                         ...(this.config.featureFlags.logsUIEnabled
                           ? [
                               { label: 'Stream', app: 'logs', path: '/stream' },
@@ -161,7 +166,7 @@ export class Plugin implements InfraClientPluginClass {
                     },
                   ]
                 : []),
-              ...(capabilities.infrastructure.show
+              ...(infrastructure.show
                 ? [
                     {
                       label: metricsTitle,

x-pack/plugins/observability_solution/observability_logs_explorer/public/plugin.ts

@@ -7,13 +7,16 @@
 
 import {
   AppMountParameters,
+  AppStatus,
+  AppUpdater,
   CoreSetup,
   CoreStart,
   DEFAULT_APP_CATEGORIES,
   Plugin,
   PluginInitializerContext,
 } from '@kbn/core/public';
 import { OBSERVABILITY_LOGS_EXPLORER_APP_ID } from '@kbn/deeplinks-observability';
+import { BehaviorSubject } from 'rxjs';
 import {
   AllDatasetsLocatorDefinition,
   ObservabilityLogsExplorerLocators,
@@ -35,6 +38,7 @@ export class ObservabilityLogsExplorerPlugin
 {
   private config: ObservabilityLogsExplorerConfig;
   private locators?: ObservabilityLogsExplorerLocators;
+  private appStateUpdater = new BehaviorSubject<AppUpdater>(() => ({}));
 
   constructor(context: PluginInitializerContext<ObservabilityLogsExplorerConfig>) {
     this.config = context.config.get();
@@ -56,6 +60,7 @@ export class ObservabilityLogsExplorerPlugin
         ? ['globalSearch', 'sideNav']
         : ['globalSearch'],
       keywords: ['logs', 'log', 'explorer', 'logs explorer'],
+      updater$: this.appStateUpdater,
       mount: async (appMountParams: ObservabilityLogsExplorerAppMountParameters) => {
         const [coreStart, pluginsStart, ownPluginStart] = await core.getStartServices();
         const { renderObservabilityLogsExplorer } = await import(
@@ -123,7 +128,16 @@ export class ObservabilityLogsExplorerPlugin
     };
   }
 
-  public start(_core: CoreStart, _pluginsStart: ObservabilityLogsExplorerStartDeps) {
+  public start(core: CoreStart, _pluginsStart: ObservabilityLogsExplorerStartDeps) {
+    const { discover, fleet, logs } = core.application.capabilities;
+
+    if (!(discover?.show && fleet?.read && logs?.show)) {
+      this.appStateUpdater.next(() => ({
+        status: AppStatus.inaccessible,
+        visibleIn: [],
+      }));
+    }
+
     return {};
   }
 }