feat(ms): track TIC and BPC provenance

[nmrtist]

Summary

• Track TIC and BPC provenance independently as source chromatograms, spectrum summaries, peak-array derivations, or mixed summary/array data.
• Resolve each stream chromatogram deterministically: prefer its bound source channel, then per-spectrum summaries, and finally peak-array derivation.
• Prevent Unknown channels from standing in for TIC and prevent TIC from being reused as BPC.
• Expose the selected provenance through field metadata, Scientific Summary, and Scientific Script snapshots.
• Mark mzML, WIFF, and Waters source channels consistently, while keeping duplicate single-stream TIC/BPC channels independently accessible.
• Preserve the fixed plotx_mass_spec_v1 wire layout; persisted source channels default to source provenance without changing the payload format.
• Replace environment-dependent local fixture tests with deterministic synthetic coverage for source, derived, fallback, chromatogram-only, project round-trip, and script observability behavior.
• Document the provenance and fallback behavior in the English and Simplified Chinese importing guides.

Validation

• cargo pr-check
• cargo test -p plotx-core mass_spec_convert
• cargo test -p plotx-io mzml::tests
• npm run build from docs/ (75 pages)