fix(ui): drop duplicate in-tab Approve Translation and Approve Chunks

[nexus69420]

Summary

• Remove the in-tab Approve Translation and Approve Chunks buttons on Document Ops.
• Keep the header pipeline actions as the single approve control. Retry Translation stays in the Translation tab.

Test plan

• At translation review: Approve Translation appears only next to the stepper, not in the Translation tab
• At chunk review: Approve Chunks appears only next to the stepper, not in the Chunks tab
• Retry Translation still works from the Translation tab
• Header approve still signals the workflow as before