Subject: [PATCH 0003] pyannote env: pin torch/torchaudio 2.8 and torchcodec 0.7

The embedded pyannote env leaves torchcodec unpinned (and torch >=2.5). On fv-ml1
(2026-10-06) uv resolved torch 2.8.0+cu128 with torchcodec 0.16.0, which needs
torch >=2.11 and CUDA 13 (libnvrtc.so.13). torchcodec's import fails, so
pyannote.audio 4 has no AudioDecoder, and every Parakeet+pyannote diarization
fails with "name 'AudioDecoder' is not defined". torchcodec's own compatibility
table pairs 0.7 with torch 2.8. Pin all three together, so a fresh env resolves
the set that was verified: community-1 diarization on GPU, 3 speakers on a 4-min
clip, 11 s.

---
--- a/internal/transcription/adapters/py/pyannote/pyproject.toml
+++ b/internal/transcription/adapters/py/pyannote/pyproject.toml
@@ -4,8 +4,8 @@
 description = "Audio diarization using PyAnnote"
 requires-python = ">=3.10"
 dependencies = [
-    "torch>=2.5.0",
-    "torchaudio>=2.5.0",
+    "torch==2.8.*",
+    "torchaudio==2.8.*",
     "huggingface-hub>=0.28.1",
     "pyannote.audio==4.0.2"
 ]
@@ -18,7 +18,7 @@
 
 [tool.uv]
 override-dependencies = [
-    "torchcodec ; sys_platform != 'linux' or platform_machine != 'aarch64'"
+    "torchcodec==0.7.* ; sys_platform != 'linux' or platform_machine != 'aarch64'"
 ]
 
 [tool.uv.sources]