[Bug] Unsafe table indexing in load_actions — invalid commands crash Neovim

[PyDevC]

File: lua/model_cmp/commands.lua:109

Introduction: actions[args[1]][args[2]]() assumes both args[1] and args[2] exist and are valid keys. Any invalid :ModelCmp command crashes with a hard Lua error.

Detailed Description: No input validation exists. :ModelCmp nonexistent, :ModelCmp virtualtext nonexistent, or :ModelCmp (no args) all produce uncatchable errors.

Reproduction:

:ModelCmp nonexistent        " crashes
:ModelCmp virtualtext foo    " crashes
:ModelCmp                    " crashes

System detail: All systems.