Function try_build_execution_plan_in_dir 

pub fn try_build_execution_plan_in_dir(
    document: &DocumentAst,
    invocation: Invocation<'_>,
    working_dir: PathBuf,
) -> Result<ExecutionPlan, PlanError>

Builds a dependency-ordered execution plan from semantic AST for an explicit working directory.

Args: document: Semantic AST used by the runtime. invocation: Requested task target plus input bindings. working_dir: Directory used by runtime execution.

Returns: Dependency-expanded execution plan in DAG order.