Add SSO OAuth env vars to Dockerfile for Google, Microsoft, and GitHub

Co-authored-by: edgeofsanity76 <79632647+edgeofsanity76@users.noreply.github.com>

Dockerfile

@@ -27,6 +27,14 @@ RUN mkdir -p /app/data
 # Store the database in the volume-mountable /app/data directory
 ENV ConnectionStrings__DefaultConnection="Data Source=/app/data/budgetapp.db"
 
+# SSO / OAuth provider configuration (override at runtime with your credentials)
+ENV Authentication__Google__ClientId="" \
+    Authentication__Google__ClientSecret="" \
+    Authentication__Microsoft__ClientId="" \
+    Authentication__Microsoft__ClientSecret="" \
+    Authentication__GitHub__ClientId="" \
+    Authentication__GitHub__ClientSecret=""
+
 VOLUME ["/app/data"]
 
 ENTRYPOINT ["dotnet", "BudgetApp.dll"]