Add massive neutrino support and improve CSV/CLI output

- Add neutrino mass parameter to SpectrumConfig and CLI interface
- Update PhaseSpace component to handle neutrino mass effects properly
- Update CSV headers to show basic endpoint and all transition types
- Add --csv-verbosity option to CLI with 'full' and 'concise' options
- Fix comparison plots to properly show linear scale variations
- Add comprehensive tests for neutrino mass functionality

.llm-wiki/wiki/sources/SRC-2026-05-27-003.md

@@ -0,0 +1,41 @@
+---
+type: source
+format: web
+source_id: SRC-2026-05-27-003
+raw_path: raw/sources/SRC-2026-05-27-003/extracted.md
+captured: 2026-05-27
+status: skeleton
+---
+
+# https://jyx.jyu.fi/bitstreams/eb3a10c8-b94c-4009-8a8e-839bfddc7c58/download
+> _Original: [https://jyx.jyu.fi/bitstreams/eb3a10c8-b94c-4009-8a8e-839bfddc7c58/download](https://jyx.jyu.fi/bitstreams/eb3a10c8-b94c-4009-8a8e-839bfddc7c58/download)_
+
+## Summary
+
+[LLM: Replace with 2-3 paragraph summary of key content]
+
+> _Auto-preview: This is a self-archived version of an original article. This version may differ from the original in pagination and typographic details. Kostensalo, Joel; Suhonen, Jouni Author(s): gA-driven shapes of electron spectra of forbidden β decays in the nuclear shell model Title: Year: 2017 Version: Published version Copyright: © 2017 American Physical Society. Published in this repository with the kind permission of the publisher. Rights: Rights url: Please cite the original version: Kostensalo, J., &..._
+
+## Key Takeaways
+
+- [LLM: Most important point]
+- [LLM: Second important point]
+- [LLM: Third important point]
+
+## Entities Mentioned
+
+- [[entity-name]]
+
+## Concepts Mentioned
+
+- [[concept-name]]
+
+## Notable Quotes
+
+> [LLM: Important quote] — attribution
+
+## Source Packet
+
+- **ID:** `[[sources/SRC-2026-05-27-003]]`
+- **Extracted:** [raw/sources/SRC-2026-05-27-003/extracted.md](../raw/sources/SRC-2026-05-27-003/extracted.md)
+- **Manifest:** [raw/sources/SRC-2026-05-27-003/manifest.json](../raw/sources/SRC-2026-05-27-003/manifest.json)