fix: compress images over 5MB before sending to Anthropic API

[roomote]

Description

This PR fixes the issue where images larger than 5MB fail to upload when using the Anthropic API. The solution implements automatic image compression using the sharp library.

Problem

• Users were unable to upload images larger than 5MB
• Anthropic API has a 5MB limit for image uploads
• This resulted in API request errors

Solution

• Added sharp library for efficient image compression
• Created a compression utility that:
  • Automatically detects images over 5MB
  • Applies progressive quality reduction (up to 5 attempts)
  • Converts PNG to JPEG for better compression when needed
  • Falls back to resizing if compression alone isn't sufficient
  • Targets 90% of the 5MB limit to leave a safety margin
• Integrated compression into the image selection workflow with:
  • Progress notification during compression
  • Success message showing size reduction
  • Graceful error handling

Testing

• Added comprehensive test suite with 12 test cases covering:
  • Small images (no compression needed)
  • Large images requiring compression
  • Different image formats (JPEG, PNG, WebP)
  • Progressive quality reduction
  • Resize fallback
  • Error handling
• All tests pass successfully

User Experience

• Users see a progress notification while images are being compressed
• Compression results are displayed (e.g., "Image compressed from 6.5 MB to 4.2 MB")
• Process is transparent and non-blocking

Future Enhancements (not in this PR)

• Consider making MAX_FILE_SIZE configurable for different API providers
• Add telemetry to track compression effectiveness
• Consider caching compressed images

Fixes #8771

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Important

Adds image compression for images over 5MB using sharp, integrated into the image selection workflow with tests and dependency updates.

• Behavior:
  • Implements image compression for images over 5MB using sharp in image-compression.ts.
  • Converts PNG to JPEG for better compression and resizes if compression fails.
  • Integrated into selectImages() in process-images.ts with progress notifications.
• Testing:
  • Adds image-compression.spec.ts with 12 test cases for different image sizes and formats.
• Dependencies:
  • Adds sharp to package.json dependencies.

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[roomote]

Review Summary

I've reviewed the PR and found 1 issue that should be addressed:

• Misleading success message when compression fails - The code shows "Image compressed from X MB to X MB" when compression encounters an error and returns the original buffer. Should verify size actually decreased before showing success message.

Follow Along on Roo Code Cloud

[roomote]

When compression fails and the original buffer is returned (due to the try-catch in compressImageIfNeeded), this message will incorrectly display something like "Image compressed from 6.0 MB to 6.0 MB". The code should verify that the size actually decreased before showing a success message, or show a different message when compression fails.