refactor: remove dead export_gltf.py, cleanup rendering tasks, improve tessellation UI

- Remove export_gltf.py (Blender-based GLB export replaced by OCC direct)
- Remove unused export_gltf_for_order_line_task
- Add Ultra tessellation preset to Admin settings
- Improve tessellation preset descriptions and styling
- Minor cleanup across media, rendering, and workflow modules

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

backend/app/domains/rendering/tasks.py

@@ -506,52 +506,6 @@ def render_order_line_still_task(self, order_line_id: str, **params) -> dict:
         raise self.retry(exc=exc, countdown=30)
 
 
-@celery_app.task(
-    bind=True,
-    name="app.domains.rendering.tasks.export_gltf_for_order_line_task",
-    queue="asset_pipeline",
-    max_retries=1,
-)
-def export_gltf_for_order_line_task(self, order_line_id: str) -> dict:
-    """Export a geometry GLB directly from STEP via OCC (no STL intermediary).
-
-    Publishes a MediaAsset with asset_type='gltf_geometry'.
-    """
-    import os
-    import subprocess
-    import sys
-
-    step_path_str, cad_file_id = _resolve_step_path_for_order_line(order_line_id)
-    if not step_path_str:
-        raise RuntimeError(f"Cannot resolve STEP path for order_line {order_line_id}")
-
-    step = Path(step_path_str)
-    output_path = step.parent / f"{step.stem}_geometry.glb"
-    scripts_dir = Path(os.environ.get("RENDER_SCRIPTS_DIR", "/render-scripts"))
-    occ_script = scripts_dir / "export_step_to_gltf.py"
-
-    if not occ_script.exists():
-        raise RuntimeError(f"export_step_to_gltf.py not found at {occ_script}")
-
-    try:
-        cmd = [
-            sys.executable, str(occ_script),
-            "--step_path", str(step),
-            "--output_path", str(output_path),
-        ]
-        result = subprocess.run(cmd, capture_output=True, text=True, timeout=120)
-        if result.returncode != 0:
-            raise RuntimeError(
-                f"export_step_to_gltf.py exited {result.returncode}:\n{result.stderr[-500:]}"
-            )
-        publish_asset.delay(order_line_id, "gltf_geometry", str(output_path))
-        logger.info("export_gltf_for_order_line_task completed via OCC: %s", output_path.name)
-        return {"glb_path": str(output_path), "method": "occ"}
-    except Exception as exc:
-        logger.error("export_gltf_for_order_line_task failed for %s: %s", order_line_id, exc)
-        raise self.retry(exc=exc, countdown=15)
-
-
 @celery_app.task(
     bind=True,
     name="app.domains.rendering.tasks.export_blend_for_order_line_task",

backend/app/domains/rendering/workflow_builder.py

@@ -64,23 +64,16 @@ def _build_multi_angle(order_line_id: str, params: dict):
 
 
 def _build_still_with_exports(order_line_id: str, params: dict):
-    """Still render + parallel GLB exports (geometry + production quality).
+    """Still render + .blend export.
 
     Pipeline:
-        render_order_line_still_task → group(
-            export_gltf_for_order_line_task,
-            export_blend_for_order_line_task,
-        )
+        render_order_line_still_task → export_blend_for_order_line_task
     """
     from app.domains.rendering.tasks import (
         render_order_line_still_task,
-        export_gltf_for_order_line_task,
         export_blend_for_order_line_task,
     )
     return chain(
         render_order_line_still_task.si(order_line_id, **params),
-        group(
-            export_gltf_for_order_line_task.si(order_line_id),
-            export_blend_for_order_line_task.si(order_line_id),
-        ),
+        export_blend_for_order_line_task.si(order_line_id),
     )

backend/app/domains/rendering/workflow_executor.py

@@ -45,8 +45,7 @@ STEP_TASK_MAP: dict[StepName, str] = {
     # ── Order line stills & turntables ──────────────────────────────────
     StepName.BLENDER_STILL: "app.domains.rendering.tasks.render_order_line_still_task",
     StepName.BLENDER_TURNTABLE: "app.domains.rendering.tasks.render_turntable_task",
-    # ── GLB / asset export ───────────────────────────────────────────────
-    StepName.EXPORT_GLB_GEOMETRY: "app.domains.rendering.tasks.export_gltf_for_order_line_task",
+    # ── Asset export ─────────────────────────────────────────────────────
     StepName.EXPORT_BLEND: "app.domains.rendering.tasks.export_blend_for_order_line_task",
     # ── Steps without a dedicated standalone task (no mapping) ───────────
     # StepName.GLB_BBOX              — computed inline inside process_step_file

backend/app/domains/rendering/workflow_router.py

@@ -51,7 +51,6 @@ _STEP_CATEGORIES: dict[StepName, StepCategory] = {
     StepName.BLENDER_STILL: "rendering",
     StepName.BLENDER_TURNTABLE: "rendering",
     StepName.OUTPUT_SAVE: "output",
-    StepName.EXPORT_GLB_GEOMETRY: "output",
     StepName.EXPORT_BLEND: "output",
     StepName.STL_CACHE_GENERATE: "processing",
     StepName.NOTIFY: "output",
@@ -72,7 +71,6 @@ _STEP_DESCRIPTIONS: dict[StepName, str] = {
     StepName.BLENDER_STILL: "Render a production still image (PNG) via Blender HTTP micro-service",
     StepName.BLENDER_TURNTABLE: "Render all turntable animation frames via Blender HTTP micro-service",
     StepName.OUTPUT_SAVE: "Upload the rendered output file to storage and create a MediaAsset record",
-    StepName.EXPORT_GLB_GEOMETRY: "Export a geometry-only GLB for the 3-D viewer (no materials)",
     StepName.EXPORT_BLEND: "Save the production .blend file as a downloadable MediaAsset",
     StepName.STL_CACHE_GENERATE: "Convert STEP → STL (low + high quality) and cache next to the STEP file",
     StepName.NOTIFY: "Emit a user notification via the audit-log notification channel",