feat: include images in tasks

[lequocbinh04]

feat: include images in tasks, and change the prompt to make AI model to read the image and understand it.

Summary

this PR implements comprehensive image attachment functionality for tasks, allowing users to upload, view, and manage images that AI models can analyze during task execution

Key Features

• Multiple upload methods: Drag-and-drop, file selection, and clipboard paste
• AI integration: All executors now instruct AI models to read and analyze attached images
• Storage: Images stored securely with UUID filenames, metadata tracked in database
• UI components: New ImageUpload widget and TaskAttachments grid with lightbox preview
• API endpoints: Upload, download, and delete attachments with proper validation

Technical Changes

• Added attachments table with foreign key to tasks
• Created /api/attachments/* endpoints with 10MB file size limit
• Updated all AI executors to include attachment paths in prompts
• Enhanced task forms with image upload capability
• Implemented proper blob URL cleanup to prevent memory leaks

Some Images:

[nguyenvanduocit]

Very useful

[nguyenvanduocit]

I think the attachment section should be collapsible. style should be match with task details:

[lequocbinh04]

attachments section can be collapsible now