Fix SRF writing logic

[lispandfound]

Fixes SRF read-write logic to be more consistent with what the C code expects. Now:

• Plane header is split after the sixth value (consistent with the SRF read and write routines in EMOD3D).
• Rust parser now refuses to parse SRFs that are written with all PLANE headers on one line.
• SRF v1 outputs now also have per-plane POINTS declaration.

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.

[Copilot]

Pull request overview

Updates SRF read/write handling to align the Rust implementation with EMOD3D’s expected SRF layout, particularly around PLANE header line breaks and stricter parsing.

Changes:

• Split PLANE header writing into two lines after the 6th value to match EMOD3D formatting.
• Tightened SRF parsing by requiring an end-of-line after the 6th PLANE header token (wid), rejecting legacy one-line headers.
• Updated and expanded fixtures/tests to reflect the new header layout and validate multi-plane parsing.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
src/srf_writer.rs	Writes PLANE headers across two lines; updates writer tests/fixtures accordingly.
src/srf_parser.rs	Enforces newline after wid in PLANE headers; updates fixtures and adds a V1 multi-plane parsing test.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.