Fix personalized feed test ID collision

[koutst]

Summary

• Compare (content_type, id) pairs in test_personalized_feed_filters_only_papers instead of comparing bare IDs across the Paper and ResearchhubPost tables.
• Assert the complete result is exactly the expected paper, preserving coverage that posts are excluded.
• No production code changes.

Cause

Paper and post primary keys are generated independently and can overlap. In the failing CI run, both IDs were 132, so a correctly returned paper triggered assertNotIn(self.post.id, result_ids). The old assertion depended on test database sequence state.

Validation

• Passed: Ruff lint and formatting checks for the changed file.
• Passed: git diff --check.
• Attempted the focused Django test; it could not start because this worktree lacks config_local/db.py (ImportError: cannot import name 'db' from 'config_local'). CI validation is still required.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-03T18:34:31.534128Z	9854c54	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.82%. Comparing base (139fa82) to head (9854c54).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4071   +/-   ##
=======================================
  Coverage   85.82%   85.82%           
=======================================
  Files         752      752           
  Lines       44002    44002           
=======================================
  Hits        37763    37763           
  Misses       6239     6239           

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.