Fix solver validation, history semantics, and Numba parity

[sergioald]

Summary

Second corrective review round for LDSFL-Meander.

Fixes

• Correct Numba SL=1 sub-resonant routing so NumPy and Numba implementations agree.
• Add shared scientific parameter validation for GUI, CSV and direct solver use.
• Validate core run controls inside the solver.
• Prevent dimensional velocity outputs when a valid physical U0 is unavailable.
• Make --no-plots suppress all PNG generation.
• Write sinuosity history incrementally without duplicate rows.
• Add explicit state_step semantics while retaining legacy jt.
• Record the initial state and every completed state through step N.
• Treat failures of required numerical outputs as fatal and record run_status.json.

Validation

• 256 tests passed
• 1 environment-dependent test skipped
• 0 expected failures / xfails
• Numba backend guardrails: 4 passed
• pre-commit: passed
• Ruff: passed
• git diff --check: passed
• source distribution: built successfully
• wheel: built successfully
• twine check: passed

Scope

No physical model equations, resonance formulation, resistance/update ordering, or applicability thresholds were changed.
Package version remains 0.6.5.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 7f6679b35e

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Validate the requested GUI output units

Pass config.run.output_units to the validator rather than the resolved value. output_scales() maps every unrecognized value to "dimensionless", so a loaded or programmatically constructed GUI config with a typo such as "dimensionl" passes validation and silently produces dimensionless scientific outputs instead of reporting the invalid unit selection.

Useful? React with 👍 / 👎.