Phase 2.3 — Fix render cancellation (real Celery task ID):
- orders.py cancel endpoints: read celery_task_id from render_job_doc
instead of synthetic "render-{line_id}" which was a no-op
- render_order_line_still_task: creates RenderJobDocument at task start,
stores self.request.id as celery_task_id, writes step-level state
(RESOLVE_STEP_PATH → BLENDER_STILL) back to order_lines.render_job_doc
Phase 3.1 — Remove Pillow overlay dead code:
- blender_render.py: deleted 55-line Pillow post-processing block
(lines 798-851, green bar + model name label)
- transparent_bg=True is always passed; the else branch was unreachable
- Removed mention from script docstring
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>