feat: implement SWR cache-control headers and resolve edge runtime compilation errors (#4152)

[thakurakanksha288]

🛠️ Description

close #4152

This PR implements fine-tuned Stale-While-Revalidate (SWR) Cache-Control headers for the dynamic SVG generation routes inside app/api/streak/route.ts.

Without proper cache directives, high burst traffic from embedded GitHub Profile README views forces repeated, expensive upstream GraphQL API queries. This implementation configures edge networks (Vercel/Cloudflare) to instantaneously serve cached monolith SVGs while asynchronously refreshing data fields in the background.

Additionally, this PR addresses critical compilation blocks and Edge runtime errors discovered during local environment verification.

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🚀 Changes Implemented

• SWR Cache Header Strategies: Configured custom CDN cache metrics utilizing maximum age constraints mapped dynamically against daily UTC/local midnight expirations (public, max-age=3600, s-maxage=${secondsToMidnight}, stale-while-revalidate=86400, must-revalidate).
• Web Crypto Standardization: Swapped the standard Node.js native crypto module for standard crypto.subtle.digest calls, successfully eliminating Next.js Serverless/Edge environment compilation warnings.
• Syntax & Structural Alignment: Fixed broken block nesting boundaries between GET handlers and error-response mapping handlers.
• Historical Query Caching: Forced long-lived immutable cache headers (public, s-maxage=31536000, immutable) for past year analytics queries since historical commit distributions never change.

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🧪 Verification & Local Testing

1. Verified server stability locally via npm run dev with Next.js compiling cleanly without import squiggles.
2. Verified runtime performance via curl queries:

   curl -I "http://localhost:3000/api/streak?user=thakurakanksha288"
   
   closes #4152
   

[vercel]

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[github-actions]

🚨 Hey @thakurakanksha288, the CI Pipeline is failing on this PR and it has been marked as status:blocked.

Please fix the issues before this can be reviewed. Here's how:

1. Run checks locally before pushing:

npm run format:check   # Check Prettier formatting
npm run lint           # Run ESLint
npm run typecheck      # TypeScript type check
npm run test           # Run unit tests (Vitest)
npm run build          # Verify production build passes

2. Auto-fix common issues:

npm run format         # Auto-fix formatting with Prettier
npm run lint -- --fix  # Auto-fix lint errors where possible

3. Check the full failure log here:
👉 View CI Run

Once you push a fix and the CI passes, the status:blocked label will be removed automatically. 💪

[thakurakanksha288]

Hi @JhaSourav07,

I have updated the streak API route (app/api/streak/route.ts) to fix the failing CI checks.

🛠️ What changed?
Cache Headers Re-aligned: Updated the Cache-Control strings across different views (including historical years and refresh overrides) to perfectly match the literal strings expected by the test suite.

Web Crypto Environment Fallback: Added a lightweight string hashing fallback mechanism to generateETag so it no longer breaks or throws runtime errors in simulated Jest/Vitest Node testing environments where crypto.subtle might be undefined.

Prettier Mismatches Cleaned: Fixed nested multi-line indentation layouts to fully conform with the repository's strict formatting standards.

The test suite and Prettier check are now passing perfectly. Ready for your review and merge! 🚀

Thanks!

[thakurakanksha288]

hi @JhaSourav07, kindly check once again.

[Aamod-Dev]

Appreciate you taking the time to submit this PR. I went through the implementation and the approach looks solid.

Everything looks good. Approving this now.