Fix VS Code interpreter path to use relative path

${workspaceFolder} is not expanded in python.defaultInterpreterPath;
use a relative path instead.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.vscode/settings.json

@@ -1,5 +1,5 @@
 {
-  "python.defaultInterpreterPath": "${workspaceFolder}/.venv/bin/python3",
+  "python.defaultInterpreterPath": ".venv/bin/python3",
   "python.terminal.activateEnvironment": true,
   "jupyter.notebookFileRoot": "${workspaceFolder}"
 }