Optimize MS2 spectrum peak shrinking hot path

[YukiMatsuzawa]

Summary

• replace result.Any() with constant-time result.Count > 0 in Ms2ScanMatching.ShrinkPeaks
• preserve peak merging behavior while avoiding repeated LINQ enumeration in the MS2 matching hot path

Ten performance improvement candidates

1. Optimize Ms2ScanMatching.ShrinkPeaks empty-result check — high impact/trivial effort; implemented here.
2. Cache SpectrumViewer mass/intensity ranges — medium-high impact/low effort; avoid repeated Min/Max traversals.
3. Use a HashSet for SpectrumViewer duplicate-drop checks — medium impact/low effort.
4. Avoid sorting every MolecularNetworking edge before degree filtering — high impact for large networks/low-medium effort.
5. Index chemical ontology membership checks — medium-high impact/medium effort.
6. Reduce intermediate allocations in spectrum normalization — medium impact/low effort.
7. Improve MsScanMatching candidate availability indexing — high impact for large peak sets/medium effort.
8. Reuse isotope-profile ordering — medium impact/medium effort.
9. Replace repeated enumerable Count calls — low-medium impact/low effort.
10. Batch SpectrumViewer axis recalculation notifications — medium UI impact/medium effort.

Validation

• dotnet restore tests\Common\CommonStandardTests\CommonStandardTests.csproj
• dotnet test tests\Common\CommonStandardTests\CommonStandardTests.csproj --no-restore --verbosity minimal