feat: add organization-scoped contribution filtering

[sureshsuriya]

Description

Fixes #7483

This PR adds support for organization-scoped contribution filtering.

Summary

• Added an optional org query parameter to the GitHub and Wrapped API endpoints.
• Added validation for the org parameter.
• Updated the GitHub contribution fetching logic to support organization-scoped queries.
• Updated cache keys to include the organization filter and avoid cache collisions.
• Added unit and integration tests covering the new functionality while preserving existing behavior when org is not provided.

Pillar

• 🎨 Pillar 1 — New Theme Design
• 📐 Pillar 2 — Geometric SVG Improvement
• 🕐 Pillar 3 — Timezone Logic Optimization
• 🛠️ Other (Bug fix, refactoring, docs)

Visual Preview

N/A (API/backend feature with no visual UI changes)

Checklist before requesting a review:

• I have read the CONTRIBUTING.md file.
• I have tested these changes locally (localhost:3000/api/streak?user=YOUR_USERNAME).
• I have run npm run format and npm run lint locally and resolved all errors (CI will fail otherwise).
• My commits follow the Conventional Commits format (e.g., feat(themes): ..., fix(calculate): ...).
• I have updated README.md if I added a new theme or URL parameter.
• I have started the repo.
• I have made sure that I have only one commit to merge in this PR.
• The SVG output matches the CommitPulse "premium quality" aesthetic standard (no raw elements, smooth animations, correct fonts).
• (Recommended) I joined the CommitPulse Discord community for contributor discussions, mentorship, and faster PR support.

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[github-actions]

📦 Next.js Bundle Size Report (Gzipped Sizes)

Asset	PR Size	Base Size	Difference	Status
static/chunks/9389-[hash].js	6.80 KB	6.79 KB	+0.01 KB (+0.19%)	🔴 Regression

📊 Summary of Totals

Category	PR Size	Base Size	Difference
Total JS	3910.77 KB	3910.49 KB	+0.28 KB (+0.01%)
Total CSS	326.92 KB	326.92 KB	0 B