Enhance devcontainer setup by upgrading pip and ensuring virtual environment configuration during installation

Author: m-messer

.devcontainer/devcontainer.json

@@ -1,7 +1,8 @@
 {
   "name": "evaluatePython",
   "image": "mcr.microsoft.com/devcontainers/python:1-3.12-bookworm",
-  "postCreateCommand": "pip install poetry==1.8.3 && poetry install",
+  "postCreateCommand": "python -m pip install --upgrade pip && python -m pip install poetry==1.8.3 && poetry config virtualenvs.in-project true && poetry install",
+  "postStartCommand": "python -m venv .venv >/dev/null 2>&1 || true && . .venv/bin/activate && poetry install",
   "forwardPorts": [8080],
   "customizations": {
     "vscode": {