fix(analyzers): unblock main — S3241 fires on three unused-return extension methods

[emeraldleaf]

Summary

Main has been broken since #63 (analyzers bump) landed. SonarAnalyzer's tightened S3241 rule now fires on three pre-existing private extension methods in `NextAurora.ServiceDefaults/Extensions.cs`:

```
error S3241: Change return type to 'void'; not a single caller uses the returned value.
Extensions.cs:107 AddOpenTelemetryExporters
Extensions.cs:169 AddDefaultAuthentication
Extensions.cs:234 AddNextAuroraApiVersioning
```

Every Dependabot rebase since #63 has been failing CI with these three errors, blocking #35, #36, #61 from merging.

The fix

Three private `TBuilder`-returning helpers had every caller invoke them as statements (`builder.AddOpenTelemetryExporters();`) with the return discarded. The rule is correctly identifying dead returns. Changes return type to `void`, drops the `return builder;` statements, and converts the early-return in `AddDefaultAuthentication` from `return builder;` to bare `return;`.

Three methods, +4/-10 lines. No behavior change, no caller change.

Verification

• `dotnet build NextAurora.ServiceDefaults/...` → 0 warnings, 0 errors
• Full solution build → 0 errors, 1 pre-existing CS0436 warning in benchmarks (unrelated to this change)

Unblocks

After this lands:
```bash
for pr in 35 36 61; do gh pr comment $pr --body "@dependabot rebase"; done
```

The Dependabot bumps + the doc-PR queue should all go green on rebase.

Pattern note

This is the kind of analyzer-bump regression that's worth catching at the PR-review stage. A path-instruction in `.coderabbit.yaml` for `NextAurora.ServiceDefaults/Extensions.cs` or `**/*Extensions.cs` files could remind reviewers to check that extension-method return values are actually consumed. Not blocking — main is the priority right now — but worth a small encoding pass later.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Refactor
  • Internal code optimization with no user-visible impact.

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 8a286aa4-39eb-4565-a253-68a383d51611

📥 Commits

Reviewing files that changed from the base of the PR and between b8a1201 and 2cf046f.

📒 Files selected for processing (1)

• NextAurora.ServiceDefaults/Extensions.cs

---

Walkthrough

Three private extension helper methods in NextAurora.ServiceDefaults/Extensions.cs are refactored to return void instead of TBuilder. Return statements are removed, and early-exit returns are simplified to bare return statements.

Changes

Extension Method Return-Type Refactoring

Layer / File(s)	Summary
Private helper method return-type refactoring NextAurora.ServiceDefaults/Extensions.cs	AddOpenTelemetryExporters, AddDefaultAuthentication, and AddNextAuroraApiVersioning change from TBuilder return type to void. All trailing return builder; statements are removed. Early-exit return builder; in AddDefaultAuthentication simplifies to bare return;. Call sites remain as standalone statements without chaining.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 16.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: fixing a SonarAnalyzer rule S3241 violation by converting three unused-return extension methods to return void.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/s3241-return-void-extensions

---

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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