fix: add Git to Dockerfile for django-allauth fork dependency

The docker build was failing because uv sync tried to clone the
django-allauth fork repository but Git was not available in the
python:3.12-slim container.

Changes:
- Install git package via apt-get in Dockerfile
- Clean up apt cache to minimize image size
- Enables successful docker build with git-based dependencies

Resolves docker build error:
"Git executable not found. Ensure that Git is installed and available."

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: heysamtexas

Dockerfile

@@ -1,5 +1,10 @@
 FROM python:3.12-slim
 
+# Install system dependencies
+RUN apt-get update && apt-get install -y \
+    git \
+    && rm -rf /var/lib/apt/lists/*
+
 # Install uv
 COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/