feat(onboarding): Gate SCM_PROJECT_DETAILS step with feature flag

When `onboarding-scm-project-details` flag is absent, skip the project
details step and auto-create the project with defaults (platform key as
name, first admin team, default alert rules) during the platform
features Continue action.

Refs VDY-82

Author: jaydgoss

static/app/views/onboarding/onboarding.spec.tsx

@@ -630,7 +630,7 @@ describe('Onboarding', () => {
 
   describe('SCM onboarding flow', () => {
     const scmOrganization = OrganizationFixture({
-      features: ['onboarding-scm-experiment'],
+      features: ['onboarding-scm-experiment', 'onboarding-scm-project-details'],
     });
 
     const githubProvider = GitHubIntegrationProviderFixture({

static/app/views/onboarding/onboarding.tsx

@@ -170,7 +170,15 @@ export function OnboardingWithoutContext() {
     feature: 'onboarding-scm-experiment',
   });
 
-  const onboardingSteps = hasScmOnboarding ? scmOnboardingSteps : legacyOnboardingSteps;
+  const hasProjectDetailsStep = organization.features.includes(
+    'onboarding-scm-project-details'
+  );
+
+  const scmSteps = hasProjectDetailsStep
+    ? scmOnboardingSteps
+    : scmOnboardingSteps.filter(s => s.id !== OnboardingStepId.SCM_PROJECT_DETAILS);
+
+  const onboardingSteps = hasScmOnboarding ? scmSteps : legacyOnboardingSteps;
 
   const stepObj = onboardingSteps.find(({id}) => stepId === id);
   const stepIndex = onboardingSteps.findIndex(({id}) => stepId === id);

static/app/views/onboarding/scmPlatformFeatures.spec.tsx

@@ -10,6 +10,8 @@ import {
   OnboardingContextProvider,
   type OnboardingSessionState,
 } from 'sentry/components/onboarding/onboardingContext';
+import {ProjectsStore} from 'sentry/stores/projectsStore';
+import {TeamStore} from 'sentry/stores/teamStore';
 import * as analytics from 'sentry/utils/analytics';
 import {sessionStorageWrapper} from 'sentry/utils/sessionStorage';
 
@@ -72,6 +74,8 @@ describe('ScmPlatformFeatures', () => {
   beforeEach(() => {
     jest.clearAllMocks();
     sessionStorageWrapper.clear();
+    ProjectsStore.loadInitialData([]);
+    TeamStore.loadInitialData([]);
   });
 
   afterEach(() => {

static/app/views/onboarding/scmPlatformFeatures.tsx

@@ -1,4 +1,5 @@
 import {useCallback, useEffect, useMemo, useState} from 'react';
+import * as Sentry from '@sentry/react';
 import {LayoutGroup, motion} from 'framer-motion';
 import {PlatformIcon} from 'platformicons';
 
@@ -7,6 +8,7 @@ import {Container, Flex, Grid, Stack} from '@sentry/scraps/layout';
 import {Select} from '@sentry/scraps/select';
 import {Heading} from '@sentry/scraps/text';
 
+import {addErrorMessage} from 'sentry/actionCreators/indicator';
 import {closeModal, openConsoleModal, openModal} from 'sentry/actionCreators/modal';
 import {LoadingIndicator} from 'sentry/components/loadingIndicator';
 import {SupportedLanguages} from 'sentry/components/onboarding/frameworkSuggestionModal';
@@ -16,13 +18,17 @@ import {
   getDisabledProducts,
   platformProductAvailability,
 } from 'sentry/components/onboarding/productSelection';
+import {useCreateProject} from 'sentry/components/onboarding/useCreateProject';
 import {platforms} from 'sentry/data/platforms';
 import {t} from 'sentry/locale';
 import type {OnboardingSelectedSDK} from 'sentry/types/onboarding';
+import type {Team} from 'sentry/types/organization';
 import type {PlatformIntegration, PlatformKey} from 'sentry/types/project';
 import {trackAnalytics} from 'sentry/utils/analytics';
 import {isDisabledGamingPlatform} from 'sentry/utils/platform';
 import {useOrganization} from 'sentry/utils/useOrganization';
+import {useProjects} from 'sentry/utils/useProjects';
+import {useTeams} from 'sentry/utils/useTeams';
 import {ScmFeatureSelectionCards} from 'sentry/views/onboarding/components/scmFeatureSelectionCards';
 import {ScmPlatformCard} from 'sentry/views/onboarding/components/scmPlatformCard';
 
@@ -84,8 +90,17 @@ export function ScmPlatformFeatures({onComplete}: StepProps) {
     setSelectedPlatform,
     selectedFeatures,
     setSelectedFeatures,
+    createdProjectSlug,
+    setCreatedProjectSlug,
   } = useOnboardingContext();
 
+  const {teams, fetching: isLoadingTeams} = useTeams();
+  const {projects, initiallyLoaded: projectsLoaded} = useProjects();
+  const createProject = useCreateProject();
+  const hasProjectDetailsStep = organization.features.includes(
+    'onboarding-scm-project-details'
+  );
+
   const [showManualPicker, setShowManualPicker] = useState(false);
 
   useEffect(() => {
@@ -306,14 +321,54 @@ export function ScmPlatformFeatures({onComplete}: StepProps) {
     }
   }
 
-  function handleContinue() {
+  async function handleContinue() {
     // Persist derived defaults to context if user accepted them
     if (currentPlatformKey && !selectedPlatform?.key) {
       setPlatform(currentPlatformKey);
     }
     if (!selectedFeatures) {
       setSelectedFeatures(currentFeatures);
     }
+
+    if (!hasProjectDetailsStep) {
+      // Auto-create project with defaults when SCM_PROJECT_DETAILS step is skipped
+      const platform =
+        selectedPlatform ??
+        (currentPlatformKey
+          ? toSelectedSdk(getPlatformInfo(currentPlatformKey)!)
+          : undefined);
+      if (!platform) {
+        return;
+      }
+
+      // If the onboarding context still holds a created project slug (e.g.
+      // the user went back after the project received its first event),
+      // reuse it instead of creating a duplicate.
+      if (createdProjectSlug && projects.some(p => p.slug === createdProjectSlug)) {
+        onComplete(undefined, {product: currentFeatures});
+        return;
+      }
+
+      const firstAdminTeam = teams.find((team: Team) =>
+        team.access.includes('team:admin')
+      );
+
+      try {
+        const project = await createProject.mutateAsync({
+          name: platform.key,
+          platform,
+          default_rules: true,
+          firstTeamSlug: firstAdminTeam?.slug,
+        });
+        setCreatedProjectSlug(project.slug);
+        onComplete(undefined, {product: currentFeatures});
+      } catch (error) {
+        addErrorMessage(t('Failed to create project'));
+        Sentry.captureException(error);
+      }
+      return;
+    }
+
     onComplete();
   }
 
@@ -459,7 +514,12 @@ export function ScmPlatformFeatures({onComplete}: StepProps) {
                 features: currentFeatures,
               }}
               onClick={handleContinue}
-              disabled={!currentPlatformKey}
+              disabled={
+                !currentPlatformKey ||
+                createProject.isPending ||
+                (!hasProjectDetailsStep && (isLoadingTeams || !projectsLoaded))
+              }
+              busy={createProject.isPending}
             >
               {t('Continue')}
             </Button>