- **Removed the per-MIME "Embedder" GUI control from admin Filetype Defaults (issue #2114).**
  `PipelineSettings.preferred_embedders` was editable per-MIME-type via
  `frontend/src/components/admin/system_settings/FiletypeDefaults.tsx`, but it
  had zero effect at ingest: `_apply_dual_embedding_strategy`
  (`opencontractserver/tasks/embeddings_task.py`) always resolves the single
  global `default_embedder`. Wiring per-MIME resolution into the real ingest
  path was deliberately rejected — that "default" embedding backs a shared,
  cross-corpus vector index, and letting different MIME types resolve to
  different embedder classes/dimensions there would fragment it. Removed the
  Embedder column/stage from `FiletypeDefaults.tsx`/`types.ts`/`config.ts`
  (embedders remain configurable via the global "Default Embedder" picker and
  listable in the Component Library) and deleted the dead resolvers
  `find_embedder_for_filetype`/`get_default_embedder_for_filetype`
  (`opencontractserver/pipeline/utils.py`), which had no live production
  caller — the only consumer, `get_embedder()`
  (`opencontractserver/utils/embeddings.py`), never received a `mimetype`
  argument from any real call site. `preferred_embedders` remains a valid,
  GraphQL-API-only field (query/mutation unchanged) for anyone who wants to
  set it directly; it is simply no longer editable through the admin GUI.
