test(tests): warning-zero follow-on #710 — clear 3 xUnit analyzer warnings (5czj9v [2])

[jsboige]

Tests/ warning-zero follow-on #710 — clear 3 xUnit analyzer warnings

Follow-on to the #710 nullable-cleanup (plan complete via 8 PR #727-#734 merged). Dispatch 5czj9v [2] SECONDAIRE. Clears the 3 residual xUnit-analyzer warnings in Tests/ (the nullable family hit 0 in #710; these are the remaining non-CS analyzer warnings).

Fixes (3 distinct, all additive annotation or async — no logic change)

File	Line	Code	Fix	Rationale
HarvestManagerExpectedImageCountTests.cs	L56	xUnit1012	string rsstyle → string? rsstyle	Theory has [InlineData(10,3,null,10)] (L52) deliberately passing null rsstyle to pin the "null rsstyle = no grouping" branch of ComputeExpectedImageCount. Intentional null test input
LocalizedFileNameContractTests.cs	L30	xUnit1012	string fileName → string? fileName	Theory has [InlineData(null)] (L28) pinning the GetLocalizedFileName guard clause (null returned as-is). Same intentional-null idiom
OwlAdapterRegressionTests.cs	L306+L319	xUnit1031	public void → public async Task + .Wait() → await	xUnit1031 flags blocking Task.Wait() in test methods; canonical fix is async/await. Tests OWL2XML serialization to temp file (no sync-context → no deadlock risk either way). Test name unchanged

DoD (measured on this branch, base master 9ed2e789)

• dotnet build Tests.csproj --no-incremental: xUnit warnings 3→0. 0 errors.
• dotnet test --filter (HarvestManagerExpected|LocalizedFileName|OwlAdapterRegression): 41/41 pass.
• dotnet test (full): 587 pass / 1 fail (OWL feat(ontology): Publish OWL ontology to public endpoint #133 permanent) / 5 skip (docs(repo): test-skips inventory — 4 OAuth-gated legit + 1 Magick.NET deferred-bug (dispatch ynv05a idle) #719). 0 regression.

Residual — irréductible-infra, hors-scope Tests/ DoD

MSB3073 ×1 distinct on the MAIN project (Argumentum.AssetConverter.csproj, NOT Tests): the Microsoft.XmlSerializer.Generator PackageReference (L25) sgen target exits code 1 at build. This is a main-project build-infra warning, not a Tests/ code warning — it appears in the Tests build log only via the Tests→main project dependency.

The DoD scope is "dotnet build Tests → 0 warning (ou irréductible documenté)". Suppressing MSB3073 would require touching the main csproj:

• Out of scope for this tests-only lane (main project is zero-CS-warning stable per build: eliminate all CS compiler warnings (zero-warning build for v0.9.0) #587).
• The SGEN package may be load-bearing for ExtendedXmlSerializer — disabling it blindly risks a runtime regression.
• Follow-up: separate main-project investigation to decide suppress (<XmlSerializerGenerator...> off) vs document as irréductible-infra. Not bundled here.

Non-goals

• 0 write under Cards/. 0 production / card-rendering code changed. Tests-only.
• 0 main-project csproj change (MSB3073 follow-up is a separate investigation).

Base 9ed2e789. Dispatch 5czj9v [2] SECONDAIRE.

🤖 Generated with Claude Code

Co-authored-by: Claude-Code noreply@anthropic.com