feat: Add file attachments and inline image uploads to comments and card descriptions

[flrxnt]

This pull request adds support for file and image uploads directly within the rich text editor, allowing users to drag-and-drop or paste files into comments and card descriptions. It introduces a new custom file attachment node for non-image files, integrates image handling via Tiptap's image extension, and implements a secure API endpoint for serving uploaded files. The changes also ensure that the UI updates appropriately after uploads.

Closes #377

Editor and File Upload Enhancements:

• Added support for pasting and dragging files (images and other files) into the editor. Images are rendered inline, while other files are shown as download links using a new custom FileAttachmentNode. Both are uploaded via a new uploadFile helper and the UI is refreshed after upload. (apps/web/src/components/Editor.tsx, apps/web/src/components/FileAttachment/FileAttachmentNode.tsx, apps/web/src/components/FileAttachment/FileAttachmentNodeView.tsx) [1] [2] [3] [4] [5]
• Integrated the Tiptap image extension (@tiptap/extension-image) to handle inline images. (apps/web/package.json, pnpm-lock.yaml) [1] [2]
• Updated editor props and usage to accept cardPublicId and onFileUpload callbacks, ensuring the correct card is associated with uploads and the UI is invalidated after changes. (apps/web/src/components/Editor.tsx, apps/web/src/views/card/index.tsx, apps/web/src/views/card/components/Comment.tsx, apps/web/src/views/card/components/NewCommentForm.tsx) [1] [2] [3] [4] [5]

Backend / API:

• Added a new authenticated, rate-limited API endpoint (/api/media/[attachmentPublicId]) to securely serve uploaded attachments, with permission checks and S3 URL generation. (apps/web/src/pages/api/media/[attachmentPublicId].ts) (apps/web/src/pages/api/media/[attachmentPublicId].tsR1-R66)

UI Improvements:

• Added custom styling for images and file attachments in the editor for a consistent and user-friendly appearance. (apps/web/src/components/Editor.tsx, apps/web/src/components/FileAttachment/FileAttachmentNodeView.tsx) [1] [2]

These changes together provide a seamless and secure file upload experience in the editor, supporting both images and other file types, with immediate feedback and proper permissions handling.