Push translations to Bitbucket

Creates a Pull Request on Bitbucket with the latest translations. For each file+language: fetches the existing file from the repo, merges with database translations (DB takes precedence), compiles to the configured format, pushes to a new branch, and creates a PR. Supports JSON, PO, Android XML, and iOS Strings formats. Requires `canEditTranslations` permission.

curl -X POST "https://example.com/api/projects/497f6eca-6276-4993-bfeb-53cbbbba6f08/bitbucket/push" \  -H "Content-Type: application/json" \  -d '{    "title": "string"  }'

{  "success": true,  "pr_url": "string",  "pr_id": 0}