[Feature]: Complete SIST scientific regression coverage

[harryswift01]

Feature Request

Problem / Motivation

The current regression suite protects the competition algorithm (A), but SIST also supports melting (M), Z-DNA (Z), and cruciform (C) calculations.

These pathways should also be protected before the 1.0.0 release.

Proposed Solution

• Retain the existing A regression test.
• Add representative regression cases for M, Z, and C.
• Compare deterministic scientific values against reviewed reference outputs.
• Continue excluding runtime from comparisons.
• Define the expected output fields for each supported mode.
• Resolve the status of the additional fields present only in the inherited competition executable.

Alternatives Considered

• Rely only on the existing competition regression test.

Expected Impact

• Protects all supported calculation modes against numerical drift.
• Makes future regressions easier to identify.
• Defines the expected scientific output for the 1.0.0 release.

Additional Context

The existing competition baseline should remain unchanged unless a scientifically justified change is explicitly reviewed.