Initial commit: Prodigit 3366G DC Electronic Load RS-232 driver and CLI

Python package for controlling the Prodigit 3366G (600V/420A/6kW) over
RS-232 serial. Includes driver with full command support (CC/CR/CV/CP
modes, measurements, battery test, OCP/OPP, dynamic mode, limits) and
CLI tool with identify, measure, monitor, live graph, and raw send.

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

.gitignore

@@ -0,0 +1,10 @@
+# Python-generated files
+__pycache__/
+*.py[oc]
+build/
+dist/
+wheels/
+*.egg-info
+
+# Virtual environments
+.venv