- `[2026-07-08]` **T1 DPO leg is RUNNING (unblocked) — 2 fixes applied to deployed backend.py.**
  Blocker resolved: (1) **mtf-dev's v0.0.42 stub** `_stub_missing_optional_integrations` (last-resort sys.meta_path
  finder → missing mergekit/llm_blender/weave resolve to MagicMock, never called → zero numerics risk; applied
  VERBATIM to deployed `src/model_training_forge/train/backend.py` after `_unsloth_available()` + call-site before
  `from trl import DPOTrainer`); (2) **my cosmetic `warnings_issued` shim** (trl-0.24 DPOTrainer.__init__:405 does
  `model.warnings_issued["estimate_tokens"]=True` for warning-suppression; custom Qwen3_5 class under transformers
  5.5.0 lacks the attr → `if not hasattr(model,"warnings_issued"): model.warnings_issued={}` before the
  DPOTrainer(...).train() at backend.py:305 — cosmetic, zero training impact). Both edits are on the DEPLOYED
  un-git'd copy only → **mtf-dev must canonicalize the warnings_issued shim into their repo** (told them). DPO
  confirmed training: model loaded (851 shards), full 1196 pairs processed, in precompute_ref_log_probs (GPU0 93%
  util, 54.8GB). Completion watcher armed (bg task) → restore gen+rp + verify dpo_adapter + ping mtf-dev on exit.
  gen+rp STOPPED for the run (authorized window). Output → data/spike/dpo_adapter.