- Move MimeTypeToFileTypes and FileTypeToMimeType mappings to dedicated FileTypeMimeTypeMapping enum file
- Add empty content validation for file attachments
- Add PDF support for Gemini
- Display attachment references in user messages with file info
- Fix OpenAI unsupported mime type message formatting
- Improve URI list handling in InputService to include text/plain
- Update chat area padding and styling for better attachment display
- Prevent drag selection on chat padding element
- Update test assertions for new unsupported mime type message format
refactor: standardize file type and MIME type handling across AI providers
Introduce centralized MimeType enum and bidirectional mappings between file types and MIME types. Update Claude, Gemini, and OpenAI implementations to use consistent MIME type validation. Add file attachment support via drag-and-drop and paste in chat input. Expand supported file type detection to include programming languages, config files, and documentation formats.
