Diff engine and reporting primitives for netform_ir::Document.

This crate builds comparison views from lossless IR documents, applies explicit normalization and ordering policies, and emits deterministic edits.

Primary entrypoints:

• diff_documents
• format_markdown_report
• build_plan

Example

use netform_diff::{diff_documents, NormalizeOptions};
use netform_ir::parse_generic;

let left = parse_generic("hostname old\n");
let right = parse_generic("hostname new\n");
let diff = diff_documents(&left, &right, NormalizeOptions::default()).unwrap();
assert!(diff.has_changes);