Add support for gpu-rent.vars and enhance git update functionality

- Updated .gitignore to include gpu-rent.vars.
- Modified env.example to introduce the UPDATE_GIT variable for controlling git updates during execution.
- Implemented Import-GpuRentVars function in gpu-rent.ps1 to load environment variables from gpu-rent.vars.
- Enhanced gpu-rent.sh to support loading variables from gpu-rent.vars and added logic for handling default and extra arguments.
- Updated CLI documentation to reflect the new gpu-rent.vars file and its usage in configuration.
- Improved bootstrap and provisioning logic to conditionally perform git updates based on the new configuration.

tests/test_civitai_fetch.py

@@ -0,0 +1,35 @@
+from pathlib import Path
+
+from gpu_rent.remote.civitai_fetch import should_skip
+
+
+def test_should_skip_missing(tmp_path: Path):
+    skip, _ = should_skip(tmp_path / "nope.safetensors", "abc")
+    assert skip is False
+
+
+def test_should_skip_exists_no_sha(tmp_path: Path):
+    dest = tmp_path / "a.safetensors"
+    dest.write_bytes(b"weights")
+    skip, reason = should_skip(dest, "")
+    assert skip is True
+    assert "уже есть" in reason
+
+
+def test_should_skip_sha_match(tmp_path: Path):
+    dest = tmp_path / "a.safetensors"
+    dest.write_bytes(b"weights")
+    import hashlib
+
+    digest = hashlib.sha256(b"weights").hexdigest()
+    skip, reason = should_skip(dest, digest)
+    assert skip is True
+    assert "sha ok" in reason
+
+
+def test_should_not_skip_bad_sha(tmp_path: Path):
+    dest = tmp_path / "a.safetensors"
+    dest.write_bytes(b"weights")
+    skip, reason = should_skip(dest, "deadbeef" * 8)
+    assert skip is False
+    assert "перекачиваю" in reason