feat: implement Layer 2 per-file transit, RAM session, mock buffer, and tests (v0.2.0)

tests/test_safe_name.py

@@ -0,0 +1,17 @@
+import pytest
+from upload.backend.upload_refs.safe_name import safe_name
+
+
+def test_safe_name_simple():
+    assert safe_name("test.txt") == "test.txt"
+    assert safe_name("folder/subfolder/file.pdf") == "folder/subfolder/file.pdf"
+    assert safe_name("folder\\subfolder\\file.pdf") == "folder/subfolder/file.pdf"
+
+
+def test_safe_name_traversal():
+    assert safe_name("../etc/passwd") == ""
+    assert safe_name("folder/../../etc/passwd") == ""
+    assert safe_name("/root/file.txt") == "root/file.txt"
+    assert safe_name("..") == ""
+    assert safe_name("") == ""
+    assert safe_name(None) == ""