Function parse_input 

pub fn parse_input(
    input: ProfileInput,
) -> Result<(Sandbox, ProgramSpec), SandlockError>

Convert a parsed ProfileInput into a (Sandbox, ProgramSpec) pair.

Forwards each schema section’s fields to the corresponding SandboxBuilder method calls. The three private helpers (parse_fs_isolation, parse_branch_action, parse_mount_spec) handle string-to-typed-value conversions for fields that lack FromStr impls on their target types.