Feature Request: warn about water instability on Solution init

[YitongPan1]

Description

Problem
During solution initialization, certain combinations of pe and pH can lead to physically inconsistent states, such as:

• Water splitting

Currently, when such a pe–pH combination is provided, the system fails during the solution equilibrium stage, although this issue could be detected earlier during solution initialization.

Expected Behavior
When initializing a solution:

• The system should detect invalid or unstable pe–pH combinations that would cause water splitting.
• A clear and explicit error message should be raised during solution creation, explaining why the initialization failed.

Current Behavior

• The solution initialization fails to capture an error when certain pe–pH combinations are used.
• A ValueError is reported during the equilibrium stage, making it difficult to diagnose the root cause.

Suggested Improvement

• Add a water stability check during solution initialization to evaluate whether the specified pe–pH combination falls within the water stability region of the pe–pH (Eh–pH) diagram.
• Explicitly catch and report cases where:
  • Water splitting would occur
  • The water stability limits should be evaluated based on the specified temperature
• Provide a user-friendly error message at initialization time.