fix(security): constrain config-driven code execution

[XianBW (XianBW)]

Changes

• Replace eval() in feature expressions and disk expression caching with a restricted AST interpreter. Preserve registered operators and safe parameter syntax, including bounded containers, argument unpacking, indexing/slicing, and scalar conditions.
• Preserve quoted strings and necessary token boundaries during expression preprocessing and cache-key normalization.
• Replace TRA model and performance-graph name evaluation with explicit mappings.
• Require explicit, strictly boolean trusted=True for file-module imports, defaulting to refusal. Keep legacy module aliases for restoring trusted older file-based models.
• Update affected TRA/LightGBM examples, add regression coverage, and connect migration guidance to documentation entry points and actionable errors.

Compatibility and migration

Package imports and standard Alpha158/Alpha360 expressions remain supported without opt-in. File-based components must explicitly authorize their imports:

task:
  model:
    class: MyModel
    module_path: custom_modules/model.py
    trusted: true
    kwargs: {}

Direct imports use get_module_by_module_path(path, trusted=True). Each nested file component needs its own consent; there is no global grant. Top-level trusted controls module loading, while kwargs.trusted remains a constructor argument.

Configurations and imported code must still be trusted. This is not a sandbox or directory-containment policy, and module-import consent does not enable unrestricted expressions or authorize artifact deserialization. Artifact-loading changes are handled separately in #2339.

See the configuration execution migration guide for supported syntax, custom extensions, and old-model recovery.

[XianBW (XianBW)]

Local verification update:

• 18 security regression tests passed
• security tests plus handler serialization and full train/backtest pipeline: 22 passed
• repository-wide Black, Flake8, and Pylint passed
• all eight modified example YAML files parsed successfully
• removed the optional Plotly import from the registry regression test so test collection is independent of the analysis extra

The branch also contains minimal CI compatibility fixes for current Node/commitlint, Plotly, MLflow, and Windows/Python 3.8 OSQP behavior.

[XianBW (XianBW)]

Final verification: all 76 GitHub checks pass on commit ee6b4518/latest branch state, including title, CLA, pip compatibility, source builds, notebook execution, full pytest, and slow pytest matrices.