feat(nvim): reorganize and modernize Neovim configuration

- Remove deprecated config files: git-ref.lua, git-signs.lua, diffview-config.lua, lsp-lines-config.lua, neotree-config.lua, fidget-spinner.lua, silicon-config.lua, telescope-config.lua, llm.lua
- Add new configuration files: diagnostics-config.lua, git-config.lua, llm-config.lua, snacks-config.lua
- Update existing config files: base.lua, dap-config.lua, init.lua, lsp-config.lua, lualine-config.lua, noice-config.lua, octo-config.lua, toggleterm-config.lua, which-key-config.lua
- Update nvim and opencode module configurations

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

@@ -1,23 +1,18 @@
 require("base")
-require("aerial-config")
 require("autopairs-config")
 require("cmp-config")
 require("comment-config")
 require("dap-config")
-require("diffview-config")
-require("git-ref")
-require("git-signs")
+require("diagnostics-config")
+require("git-config")
 require("leap-config")
-require("llm")
+require("llm-config")
 require("lsp-config")
-require("lsp-lines-config")
 require("lualine-config")
-require("neotree-config")
 require("noice-config")
 require("numb-config")
 require("octo-config")
-require("silicon-config")
-require("telescope-config")
+require("snacks-config")
 require("toggleterm-config")
 require("ts-config")
 require("weird-chars")