feat(auth): surface is_new_user in OAuth login responses

[Zaimwa9]

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• I have read the Contributing Guide.
• I have added information to docs/ if required so people know about the feature.
• I have filled in the "Changes" section below.
• I have filled in the "How did you test this code" section below.

Changes

Google and GitHub OAuth login responses now include is_new_user, true when the login created the account. This lets the frontend distinguish OAuth signups from logins, so signup conversion events (see #7979) can also be emitted for OAuth-based signups. No model changes.

How did you test this code?

Unit tests: existing OAuth view tests extended to assert is_new_user is true for newly created users and false for existing ones.

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3 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
docs	Ignored	Preview	Jul 15, 2026 10:12am
flagsmith-frontend-preview	Ignored	Preview	Jul 15, 2026 10:12am
flagsmith-frontend-staging	Ignored	Preview	Jul 15, 2026 10:12am

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 47f0c9bb-3919-4b53-9b87-a908fe394e67

📥 Commits

Reviewing files that changed from the base of the PR and between 1c7121d and 59fd851.

📒 Files selected for processing (4)

• api/custom_auth/oauth/serializers.py
• api/custom_auth/oauth/views.py
• api/tests/unit/custom_auth/oauth/test_unit_oauth_views.py
• openapi.yaml

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📝 Walkthrough

Walkthrough

OAuth login now tracks whether authentication created a new user. Google and GitHub endpoints return the token key and is_new_user value when cookie authentication is disabled. OpenAPI definitions use the new read-only OAuthToken schema, and tests cover newly created and existing-user responses.

Estimated code review effort: 2 (Simple) | ~10 minutes

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.64%. Comparing base (1042aad) to head (59fd851).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8011   +/-   ##
=======================================
  Coverage   98.64%   98.64%           
=======================================
  Files        1497     1497           
  Lines       59287    59295    +8     
=======================================
+ Hits        58481    58489    +8     
  Misses        806      806           

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[github-actions]

Docker builds report

Image	Build Status	Security report
ghcr.io/flagsmith/flagsmith-e2e:pr-8011	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-frontend:pr-8011	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-api-test:pr-8011	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-api:pr-8011	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith:pr-8011	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-private-cloud:pr-8011	Finished ✅	Results ✅

[github-actions]

Playwright Test Results (oss - depot-ubuntu-latest-16)

 4 passed

Details

 4 tests across 3 suites
 19.6 seconds
 59fd851
 🔄 Run: #18304 (attempt 1)

Playwright Test Results (oss - depot-ubuntu-latest-arm-16)

 5 passed

Details

 5 tests across 4 suites
 50.6 seconds
 59fd851
 🔄 Run: #18304 (attempt 1)

Playwright Test Results (private-cloud - depot-ubuntu-latest-arm-16)

 6 passed

Details

 6 tests across 5 suites
 37 seconds
 59fd851
 🔄 Run: #18304 (attempt 1)

Playwright Test Results (private-cloud - depot-ubuntu-latest-16)

 5 passed

Details

 5 tests across 4 suites
 48.8 seconds
 59fd851
 🔄 Run: #18304 (attempt 1)

[github-actions]

Visual Regression

19 screenshots compared. See report for details.
View full report