chore: import upstream snapshot with attribution

backend/python/diffusers/requirements-cpu.txt

@@ -0,0 +1,24 @@
+--extra-index-url https://download.pytorch.org/whl/cpu
+diffusers==0.38.0
+opencv-python
+transformers==4.57.6
+torchvision==0.22.1
+accelerate
+git+https://github.com/xhinker/sd_embed
+peft
+sentencepiece
+torch==2.7.1
+optimum-quanto
+ftfy
+# diffusers and transformers are pinned together on purpose. transformers v5
+# restructured CLIPTextModel and dropped the `.text_model` attribute, which
+# breaks single-file Stable Diffusion loading on every released diffusers
+# (<=0.38.0); only unreleased diffusers main supports transformers v5. Tracking
+# main via git froze whichever broken pair existed at image-build time. Pin the
+# last known-good released pair so builds are reproducible and can't drift into
+# the broken window. See https://github.com/mudler/LocalAI/issues/9979
+#
+# compel is intentionally omitted: it pins transformers~=4.25, which conflicts
+# with this pin and previously forced pip into multi-hour resolver backtracking
+# storms in CI. backend.py imports it lazily and gates the COMPEL=1 env var on
+# the import succeeding, so dropping it here is safe.