fix(ci): authenticate git fetch upstream with GITHUB_TOKEN

Explicitly injects the GITHUB_TOKEN into the upstream remote URL in the agent-pr-review workflow. This prevents authentication failures when fetching the upstream repository in CI environments where plain HTTPS URLs trigger interactive credential prompts.

Co-authored-by: PR0M3TH3AN <[email protected]>

.github/workflows/agent-pr-review.yml

@@ -30,8 +30,10 @@ jobs:
           cache: 'npm'
 
       - name: Add upstream remote
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          git remote add upstream https://github.com/PR0M3TH3AN/bitvid.git || true
+          git remote add upstream https://x-access-token:${GITHUB_TOKEN}@github.com/PR0M3TH3AN/bitvid.git || true
           git fetch upstream
 
       - name: Verify upstream branch and diff