M4, #569: Combine files takes images and text files (#1032)

* M10: refuse a PNG whose header claims more than 2 GiB of pixels before allocating

The png crate's limits don't cover the caller's frame buffer, which png_image sized from the
header alone: a few-KB PNG claiming 60000x60000 RGBA made Create allocate and fill 14.4 GB.
Apply the 2 GiB ceiling TIFF pages already have. Reached from Create, Insert pages and (with
#569) Combine files.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* M4, #569: Combine files takes images and text files

PNG, JPEG, TIFF, GIF, BMP, JPEG 2000 and .txt files become PDFs as they join the Combine files
list (Add files…, drops, folder scans), so each is an ordinary row or card with its pages,
thumbnails and page range. Session::as_pdf does the conversion; PDFs pass through unread
(Combine reads them itself, with their passwords), as does a file named .pdf without a header,
which the reader may still open. doc_combine accepts the same file types, and a converted
file's bookmark drops its extension.

A file that can't be read (a damaged image or PDF, a type that can't be converted) no longer
is refused at the door: it joins the list with why in its Warnings (a red card in the grid).
Combine then asks "Leave out files that can't be read?", naming them; Combine the rest goes on
without them, Cancel changes nothing. Password-protected files still block Combine until
unlocked.

The picker offers "PDF, images and text", and the empty state, folder tooltips and folder
notices say what is accepted; translated in every full catalog (catalog hashes updated).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

parity/acrobat-features.toml

@@ -2914,8 +2914,8 @@ 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", "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."
+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_images_and_text_in_order_and_optionally_its_subfolders", "crates/ui-egui/tests/editing.rs::images_and_text_files_join_the_combine_list_as_pdfs", "crates/ui-egui/tests/editing.rs::files_that_cannot_be_read_are_listed_and_left_out_once_the_user_agrees", "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/automation/tests/automation.rs::combine_takes_images_and_text_files", "crates/engine/src/tests.rs::files_for_combine_are_made_into_pdfs_and_pdfs_pass_through", "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. Images (PNG, JPEG, TIFF, GIF, BMP, JPEG 2000) and .txt files become PDFs as they are added (#569; also in doc_combine). A file that can't be read stays in the list with why, and Combine asks before leaving it out; Office documents, HTML and other formats are not converted yet. 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"