fix: add per-forge org override to mirror workflow

Bitbucket uses workspace 'hyperpolymath-dev' instead of 'hyperpolymath'.
Add BITBUCKET_ORG variable fallback before the shared MIRROR_ORG.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Jonathan D.A. Jewell

.github/workflows/mirror.yml

@@ -43,7 +43,7 @@ jobs:
       - name: Mirror to Bitbucket
         run: |
           ssh-keyscan -t ed25519 bitbucket.org >> ~/.ssh/known_hosts
-          git remote add bitbucket git@bitbucket.org:${{ vars.MIRROR_ORG || github.repository_owner }}/${{ github.event.repository.name }}.git || true
+          git remote add bitbucket git@bitbucket.org:${{ vars.BITBUCKET_ORG || vars.MIRROR_ORG || github.repository_owner }}/${{ github.event.repository.name }}.git || true
           git push --force bitbucket main
 
   mirror-codeberg: