Optimizer: Audit space usage counts images PrintCraft added as images (#3)

Content added with Edit ▸ Add content records its image in the content stream's dictionary
(/PCAdded /Image). The audit claimed a page's content streams before its resources and
followed that reference, so an added image's bytes were reported as Content Streams and
Images showed 0 % (a 1.9 MB picture read as 99.9 % content). Resources are now claimed
first, so whatever a content stream's dictionary points at keeps its own category.

Co-authored-by: storybored379 <[email protected]>
Co-authored-by: Claude Opus 5.5 <[email protected]>

crates/optimize/tests/optimize.rs

@@ -193,6 +193,25 @@ fn space_audit_shares_the_file_out_by_kind() {
     assert!((audit.iter().map(|u| u.percent).sum::<f64>() - 100.0).abs() < 1e-6);
 }
 
+#[test]
+fn space_audit_counts_images_a_content_stream_dictionary_points_at_as_images() {
+    // Content added with Edit ▸ Add content records its image in the content stream's
+    // dictionary (/PCAdded); the image is still an image, not part of the content stream.
+    let mut doc = Document::new_empty();
+    let img = image(&mut doc, 300, 300, 3, false, None);
+    let p = page(&mut doc, &[("Im0", img)], "q 300 0 0 300 0 0 cm /Im0 Do Q");
+    let c = doc.get(p).as_dict().and_then(|d| d.reference(b"Contents")).unwrap();
+    let mut added = Dict::new();
+    added.set(b"Kind".to_vec(), Object::name("Image"));
+    added.set(b"Image".to_vec(), Object::Ref(img));
+    doc.update_dict(c, |d| d.set(b"PCAdded".to_vec(), Object::Dict(added))).unwrap();
+    let bytes = write_full(&doc, &SaveOptions { object_streams: false, ..SaveOptions::default() }).unwrap();
+    let doc = Document::open(Arc::new(bytes.clone())).unwrap();
+    let audit = audit_space(&doc, bytes.len() as u64);
+    let images = audit.iter().find(|u| u.category == SpaceCategory::Images).unwrap();
+    assert!(images.percent > 80.0, "{audit:?}");
+}
+
 #[test]
 fn invalid_links_and_unreferenced_destinations_go() {
     let mut doc = Document::new_empty();