Implement Binary Spectrum Library Form .msl

[trishorts]

binary format (.msl) is created, updated and used in search. Binary libraries also visualized in MetaDraw butterfly plots. Presently both msp and msl are co-written.

[trishorts]

Quality summary

This PR adds the open binary spectral-library format .msl to MetaMorpheus as a peer of the
existing text .msp, wired through the same spectral-library machinery. Below is a summary of the
change and the verification behind it.

What it does

• Recognition — DbForTask classifies .msl (alongside .msp) as a SpectralLibrary database entry.
• Consumption — .msl can be used as a spectral library in a search, loaded in the main-window
  database/library UI, and rendered in MetaDraw mirror plots, on par with .msp.
• Production — WriteSpectrumLibrary / UpdateSpectralLibrary now co-write both formats
  (SpectralLibrary_*.msp and SpectralLibrary_*.msl). Co-write is an intentional transitional
  state; the binary format's on-disk serialization lives in mzLib, not this PR.

Verification

• Up to date with master — merged current upstream/master; conflicts resolved (dependency +
  using directives). MERGEABLE, no conflicts.
• mzLib pinned to 1.0.582 — the published release that provides the .msl reader/writer
  (MslLibrary, MslLibraryEntry), applied consistently across all projects.
• Builds clean — full solution builds in Release with 0 errors.
• Code review addressed — a structured review of the four changed source files produced six
  findings, all resolved:
  • (perf) WriteSpectrumLibrary converted every spectrum to an MSL entry twice (the first
    materialization was dead code overwritten before use) → convert once.
  • (correctness) UpdateSpectralLibrary silently dropped entries that failed conversion → it now
    warns with the skipped count, matching WriteSpectrumLibrary, so the .msl/.msp pair
    can't diverge unnoticed.
  • (hygiene) removed duplicate using directives and reverted incidental tab/space churn.

Test coverage

• Patch coverage: 100% of changed executable lines (33/33), measured with Coverlet in Release —
  the same instrumenter Codecov consumes — comfortably clearing the 90% gate.
• Existing integration tests already exercise the happy-path co-write (WriteSpectralLibrary=true /
  UpdateSpectralLibrary=true across search, glyco, XL and MetaDraw tests).
• Fixed TestWriteSpectrumLibrary, which asserted the first SpectralLibrary* file was the .msp;
  with co-write the .msl now sorts first, so it asserts both formats are emitted.
• Added MslSpectralLibraryWriteTests covering the previously-untested invalid-entry path: an
  entry that fails conversion is skipped from the .msl (with a warning) while the .msp retains
  every spectrum; the two valid entries round-trip back through SpectralLibrary.

Notes for review

• The .msl binary encoding/versioning is out of scope here (it lives in mzLib 1.0.582).
• Co-write (.msp + .msl) is deliberate and transitional, not redundancy to remove in this PR.

Sync, review, fixes, and the added tests were prepared with Claude Code assistance (see the
Co-Authored-By trailers); all changes were built and tested locally before pushing.

[trishorts]

Manual unit-test review

All 2 unit test(s) added by this PR were reviewed individually by the author (not only by automated/AI-generated checks): 2 approved as written, 0 edited, 0 flagged.

This satisfies the author's standing AI-use policy that AI-assisted tests receive human review before relying on them. Recorded 2026-07-11 10:37.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.30%. Comparing base (3c8e0b8) to head (821eb7f).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2630   +/-   ##
=======================================
  Coverage   93.29%   93.30%           
=======================================
  Files         196      196           
  Lines       21320    21340   +20     
  Branches     3994     3997    +3     
=======================================
+ Hits        19891    19911   +20     
  Misses        893      893           
  Partials      536      536           

Flag	Coverage Δ
unittests	93.30% <100.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...aMorpheus/EngineLayer/DatabaseLoading/DbForTask.cs	100.00% <100.00%> (ø)
MetaMorpheus/TaskLayer/MetaMorpheusTask.cs	86.68% <100.00%> (+0.29%)	⬆️

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