Add failed-simulation logging for BNGsim-backed runs

[wshlavacek]

Context

Failed BNGsim-backed simulations need enough saved context for users and
developers to reproduce and diagnose failures.

Task

Add failed-simulation logging for BNGsim-backed runs.

Acceptance Criteria

• Failed BNGsim-backed runs record backend name and BNGsim version.
• Failure context includes model identity, parameter set, action/method, seed,
  and exception details.
• Generated .net or XML inputs are included or referenced when available.
• Failure records are compatible with existing PyBNF failed-simulation logging
  workflows.
• Network, NF, SBML opt-in, and Antimony paths produce useful failure messages
  where applicable.
• Tests cover at least one BNGsim network failure and one BNGsim NF failure.