Issue #263: combine, extract and split keep the PDF/X output intent and identification (#334)

Combine, extract and split built the new document from copies of the
pages and carried bookmarks, fields, layers, attachments and four Info
keys, but not the catalog's /OutputIntents, the GTS_PDFXVersion,
GTS_PDFXConformance and Trapped Info entries, or the XMP pdfxid
identification. A PDF/X file stopped being one, and a RIP or preflight
lost the intended output condition.

Extract and split now carry the output intents (with their ICC
profiles, through the same object map as the pages), the Info entries
(the version read from Info, else XMP) and a new XMP packet holding the
identification, trapping and title. The source's packet is not copied:
it can claim standards the new file no longer meets, such as PDF/UA,
whose structure tree is not copied. Combine carries the first source's
standard only when every source declares the same version, trapping
and output intents (type, condition and profile bytes).

Not yet: a warning when combine's sources disagree, and XMP dates.

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

parity/acrobat-features.toml

@@ -2698,8 +2698,8 @@ milestone = "M4"
 status = "shipped"
 commands = ["page.extract"]
 tools = ["page_extract"]
-evidence = ["crates/ui-egui/tests/editing.rs::extract_button_copies_selected_pages_to_a_new_tab", "crates/automation/tests/automation.rs::combine_extract_and_split"]
-notes = ""
+evidence = ["crates/ui-egui/tests/editing.rs::extract_button_copies_selected_pages_to_a_new_tab", "crates/automation/tests/automation.rs::combine_extract_and_split", "crates/organize/src/tests.rs::extract_and_split_keep_the_pdfx_output_intent_and_identification"]
+notes = "Carries the PDF/X output intent and identification (#263) in a new XMP packet; the source XMP (dates, other schemas) is not copied."
 
 [[feature]]
 id = "organize.extract-separate-files"
@@ -2818,8 +2818,8 @@ milestone = "M4"
 status = "shipped"
 commands = ["page.split"]
 tools = ["doc_split"]
-evidence = ["crates/ui-egui/tests/editing.rs::split_dialog_writes_one_file_per_part", "crates/organize/src/tests.rs::split_ranges_cover_every_page_once", "crates/organize/src/tests.rs::split_produces_standalone_documents_with_metadata"]
-notes = ""
+evidence = ["crates/ui-egui/tests/editing.rs::split_dialog_writes_one_file_per_part", "crates/organize/src/tests.rs::split_ranges_cover_every_page_once", "crates/organize/src/tests.rs::split_produces_standalone_documents_with_metadata", "crates/organize/src/tests.rs::extract_and_split_keep_the_pdfx_output_intent_and_identification"]
+notes = "Each part carries the PDF/X output intent and identification (#263), as Extract does."
 
 [[feature]]
 id = "organize.split-before-pages"
@@ -2890,8 +2890,8 @@ milestone = "M4"
 status = "shipped"
 commands = ["page.combine"]
 tools = ["doc_combine"]
-evidence = ["crates/organize/src/tests.rs::combine_concatenates_with_a_bookmark_per_file", "crates/ui-egui/tests/editing.rs::combining_files_opens_a_new_unsaved_tab", "crates/ui-egui/tests/editing.rs::combine_files_opens_in_its_own_tab", "crates/ui-egui/tests/editing.rs::combine_lists_size_and_warns_before_combining", "crates/ui-egui/tests/editing.rs::a_password_protected_file_is_unlocked_with_its_password_and_combined", "crates/ui-egui/tests/editing.rs::a_folder_adds_its_pdfs_in_order_and_optionally_its_subfolders", "crates/ui-egui/tests/ui.rs::pdfs_dropped_on_the_combine_tab_join_its_list", "crates/automation/tests/automation.rs::combine_extract_and_split", "crates/automation/tests/automation.rs::combine_opens_protected_files_with_their_passwords"]
-notes = "Combine files is its own tab: a table of the files (name, pages, size, modified, warnings) with column sorting, resizing and moving; files, folders (with subfolders) and open documents can be added, or dropped on the tab. Problems show before Combine (password, security settings that withhold page assembly, bad page ranges, duplicates); protected files are unlocked with their open or permissions password (also doc_combine passwords). The result is never encrypted, and is not yet offered for protection in the same step."
+evidence = ["crates/organize/src/tests.rs::combine_concatenates_with_a_bookmark_per_file", "crates/ui-egui/tests/editing.rs::combining_files_opens_a_new_unsaved_tab", "crates/ui-egui/tests/editing.rs::combine_files_opens_in_its_own_tab", "crates/ui-egui/tests/editing.rs::combine_lists_size_and_warns_before_combining", "crates/ui-egui/tests/editing.rs::a_password_protected_file_is_unlocked_with_its_password_and_combined", "crates/ui-egui/tests/editing.rs::a_folder_adds_its_pdfs_in_order_and_optionally_its_subfolders", "crates/ui-egui/tests/ui.rs::pdfs_dropped_on_the_combine_tab_join_its_list", "crates/automation/tests/automation.rs::combine_extract_and_split", "crates/automation/tests/automation.rs::combine_opens_protected_files_with_their_passwords", "crates/organize/src/tests.rs::combine_keeps_pdfx_when_every_source_agrees", "crates/organize/src/tests.rs::combine_claims_no_pdfx_when_the_sources_disagree"]
+notes = "Combine files is its own tab: a table of the files (name, pages, size, modified, warnings) with column sorting, resizing and moving; files, folders (with subfolders) and open documents can be added, or dropped on the tab. Problems show before Combine (password, security settings that withhold page assembly, bad page ranges, duplicates); protected files are unlocked with their open or permissions password (also doc_combine passwords). The result is never encrypted, and is not yet offered for protection in the same step. A PDF/X result (output intent, GTS_PDFXVersion, Trapped, XMP pdfxid) only when every source declares the same version and output intent (#263). When they differ the result claims none, and nothing reports that yet; Acrobat behaviour not observed."
 
 [[feature]]
 id = "organize.combine-bookmarks"