feat: implement authentication middleware for protected APIs

[ash1shkumar]

🚀 Description

Implemented authentication and authorization middleware for protected backend APIs using Supabase token validation.

Changes Made

• Added centralized authenticateUser middleware
• Protected task, chat, analytics, and feed routes
• Integrated Supabase token verification on backend
• Added frontend Authorization header support
• Added authenticated API calls for protected actions
• Injected authenticated user into request lifecycle (req.user)

Protected APIs

• /api/tasks
• /api/chat
• /api/feed (POST routes)
• /api/analytics

Frontend Updates

• Added Supabase session token handling
• Added Bearer token propagation for protected requests
• Updated task, chat, analytics, and feed integrations

Security Improvements

• Prevents unauthorized access to protected APIs
• Centralized authentication architecture
• Future-ready middleware-based authorization flow

Fixes #121

Expected Labels:
level3 NSoC‘26

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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!

[Shriii19]

@ash1shkumar this PR has conflict please resolve it .

[ash1shkumar]

@ash1shkumar this PR has conflict please resolve it .

@Shriii19 solved conflicts. Pls recheck when possible

[vercel]

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Project	Deployment	Actions	Updated (UTC)
flow-forge	Ready	Preview, Comment	May 30, 2026 5:37pm