feat(nvim): integrate CodeCompanion with LlamaSwap and Copilot

- Remove old code-companion-config.lua file
- Move LLM configuration to llm.lua with LlamaSwap and Copilot integration
- Add copilot-vim plugin to default.nix
- Update which-key bindings to include new CodeCompanion commands
- Configure CodeCompanion with chat, inline, and command strategies using LlamaSwap adapter
- Add memory configuration with default project files
- Update LSP configuration for CodeCompanion markdown rendering

modules/home/programs/terminal/nvim/config/lua/init.lua

@@ -2,7 +2,6 @@ require("base")
 require("aerial-config")
 require("autopairs-config")
 require("cmp-config")
-require("code-companion-config")
 require("comment-config")
 require("dap-config")
 require("diffview-config")