explicit torch dependency and PyTorch CPU index

Co-Authored-By: Trenton H <797416+stumpylog@users.noreply.github.com>

pyproject.toml

@@ -77,6 +77,7 @@ dependencies = [
   "sentence-transformers>=4.1",
   "setproctitle~=1.3.4",
   "tika-client~=0.10.0",
+  "torch~=2.7.0",
   "tqdm~=4.67.1",
   "watchdog~=6.0",
   "whitenoise~=6.9",
@@ -169,6 +170,15 @@ zxing-cpp = [
   { url = "https://github.com/paperless-ngx/builder/releases/download/zxing-2.3.0/zxing_cpp-2.3.0-cp312-cp312-linux_aarch64.whl", marker = "sys_platform == 'linux' and platform_machine == 'aarch64' and python_version == '3.12'" },
 ]
 
+torch = [
+  { index = "pytorch-cpu" },
+]
+
+[[tool.uv.index]]
+name = "pytorch-cpu"
+url = "https://download.pytorch.org/whl/cpu"
+explicit = true
+
 [tool.ruff]
 target-version = "py310"
 line-length = 88