Add comprehensive test suite achieving 99% code coverage

Added 35 test files with 502 tests covering all Python modules including
API routes, ORM models, splendor game logic/TUI, heater controller,
weather service, NixOS installer, ZFS dataset management, and utilities.
Coverage improved from 11% to 99% (2540/2564 statements covered).

https://claude.ai/code/session_01SVzgLDUS1Cdc4eh1ijETTh

tests/test_stuff_capasitor_main.py

@@ -0,0 +1,10 @@
+"""Tests for capasitor main function."""
+
+from __future__ import annotations
+
+from python.stuff.capasitor import main
+
+
+def test_capasitor_main(capsys: object) -> None:
+    """Test capasitor main function runs."""
+    main()