feat: add backend input sanitization and validation

[ash1shkumar]

🚀 Description

Implemented backend input sanitization and validation across multiple API endpoints to improve security, reliability, and data integrity.

Changes Made

• Added validation for task creation and updates
• Added status validation for task workflows
• Added message payload validation in chat APIs
• Added validation for feed item creation
• Improved error handling for invalid/empty requests
• Prevented malformed or unsafe user inputs from reaching database operations
• Improved backend response consistency

Security Improvements

• Prevented invalid task statuses
• Prevented empty update requests
• Prevented empty chat messages and missing usernames
• Added safer request handling for analytics/feed/insights APIs
• Improved API robustness against malformed payloads

Fixes #122

🛠️ Type of change

• Bug fix (non-breaking change which fixes an issue)
• Security improvement
• Backend enhancement

✅ Checklist

• Code follows project style guidelines
• Changes tested locally
• No breaking changes introduced
• Proper validation/error handling added

Expected Labels: level3 NSoC'26

[vercel]

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[github-actions]

👋 Thank you for opening this pull request! I will review your changes and assist you soon.

[ash1shkumar]

@Shriii19 This PR is ready for review. I’ve completed the implementation, tested the changes locally, and addressed the issue requirements. Please review when available. Thanks!

[vercel]

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Project	Deployment	Actions	Updated (UTC)
flow-forge	Ready	Preview, Comment	May 30, 2026 4:27pm