AppKit lacked a public text attachment class, preventing rich text documents
from embedding or inserting images.
* AppKit/CPTextView/CPTextAttachment.j:
- Implement CPTextAttachment (modelled on NSTextAttachment) supporting
initialization via data and file type, contents, file types, images,
bounds, and keyed archiving.
- Adopt a TextKit 2-style view rendering architecture that scales images
to fit text container width and triggers layout updates upon asynchronous loading.
* AppKit/CPTextView/CPTextStorage.j:
- Update attributedStringWithAttachment: to accept CPTextAttachment instances
alongside direct views, routing rendering through existing attachment pathways.
* AppKit/CPTextView/CPTextView.j:
- Implement the insertImage: action (invoking browser file pickers) and
Command-V paste handling for images.
- Configure inserted attachments with responsive view instances scaled to
text width, omitting live views during pasteboard archiving.
* AppKit/CPTextView/CPTextContainer.j:
- Adjust attachment bounds to match updated container widths during layout invalidation.
* AppKit/AppKit.j:
- Export CPTextAttachment.
* Tests/AppKit/CPTextAttachmentTest.j:
- Add test coverage for data URLs, archiving, width scaling, insertion,
and serialized text output.
* Tests/Manual/TextEditor/Resources/MainMenu.xib, MainMenu.cib:
- Add Edit > Insert Image… menu item.
* Tests/Manual/TextEditor/WORKLIST.md:
- Mark image insertion testing as completed; log remaining image tasks as open.
Rich text documents now support embedded images inserted via file selection or clipboard paste.
