execute()/resume() run UNVALIDATED definitions (load_workflow does not
validate). WorkflowDefinition stores `inputs` raw, so a non-mapping
`inputs:` block (bare `inputs:` -> None, or `inputs: []`) crashed
_resolve_inputs at `for name, input_def in definition.inputs.items()` with
AttributeError, aborting the whole run.
Return {} when inputs is not a mapping, mirroring validate_workflow's own
`isinstance(definition.inputs, dict)` check. Protects both call sites
(execute and resume); normal dict resolution is unchanged.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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