Fix/profile image duplicates

[Shubham15986]

Fix: Prevent Duplicate Profile Images and Collision Suffix Files

Problem

The media directory contained over 4,700 files, including 2,200+ duplicate groups.
Duplicates were created due to Django appending suffixes (e.g., _w30EZ0i) when saving files with existing names.

Example:

• images/username.png
• images/username_w30EZ0i.png

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Root Cause

1. Signal Amplification

• update_user_profile() was calling profile.save() on every User save
• This triggered repeated image processing even when no new image was uploaded

2. Non-idempotent Image Handling

• Image processing ran on every save (including DB reloads)
• Existing files were not deleted before saving → Django created suffixed duplicates
• Old image files were not cleaned up

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Changes Made

1. Removed unnecessary signal-driven saves

• Profile is now saved only when required (creation or explicit update)
• Eliminates repeated image processing

2. Implemented overwrite-safe image handling

• Process images only for new uploads using _committed check
• Delete existing file before saving to prevent suffix creation
• Enforce deterministic file naming (images/username.png)
• Always overwrite instead of creating new copies

3. Added cleanup logic

• Deletes previous image file when updated
• Prevents orphaned files

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Key Improvements

• Idempotent save logic (no reprocessing on repeated saves)
• No collision suffix files generated
• Automatic cleanup of old images
• Reduced unnecessary processing

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Result

• Duplicate image generation is prevented at the source
• File naming is consistent and predictable
• Storage remains clean (no accumulation of unused files)
• Image handling is stable and efficient

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Notes

• Existing duplicate files are not modified in this PR
• This fix ensures no new duplicates will be created going forward