Test/GitHub token header assertion (JhaSourav07#3047)

## Description

Fixes JhaSourav07#1104

Added tests to verify GitHub API requests include the expected token
header and that `fetchUserRepos` correctly handles paginated responses
across multiple pages.

## Pillar

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

## Visual Preview

N/A (test-only changes)

## Checklist before requesting a review:

* [x] I have read the `CONTRIBUTING.md` file.
* [x] I have tested these changes locally.
* [x] I have run `npm run format` and `npm run lint` locally and
resolved all errors.
* [x] My commits follow the Conventional Commits format.
* [ ] I have updated `README.md` if I added a new theme or URL
parameter. (Not applicable)
* [x] I have starred the repo.
* [x] 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. (Not applicable for test-only changes)
* [x] I joined the CommitPulse Discord community.

Author: JhaSourav07

package-lock.json

@@ -67,7 +67,7 @@
     "eslint-config-next": "16.2.3",
     "eslint-config-prettier": "^10.1.8",
     "husky": "^9.1.7",
-    "jsdom": "^29.0.2",
+    "jsdom": "^29.1.1",
     "lint-staged": "^15.2.11",
     "node-mocks-http": "^1.17.2",
     "postcss": "^8.5.9",