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/snacks-config.lua

@@ -0,0 +1,23 @@
+-- Snacks Setup
+local snacks = require("snacks")
+snacks.setup({
+	input = { enabled = true, style = "popup" },
+	select = { enabled = true, style = "popup" },
+})
+
+-- Create KeyMaps
+vim.keymap.set("n", "<leader>fb", snacks.picker.buffers, { desc = "Buffers" })
+vim.keymap.set("n", "<leader>fd", snacks.picker.diagnostics, { desc = "Diagnostics" })
+vim.keymap.set("n", "<leader>ff", snacks.picker.files, { desc = "Find Files" })
+vim.keymap.set("n", "<leader>fg", snacks.picker.grep, { desc = "Grep Files" })
+vim.keymap.set("n", "<leader>fh", snacks.picker.help, { desc = "Help Tags" })
+vim.keymap.set("n", "<leader>fj", snacks.picker.jumps, { desc = "Jump List" })
+vim.keymap.set("n", "<leader>fl", function() snacks.terminal("lazygit") end, { desc = "LazyGit" })
+vim.keymap.set("n", "<leader>fp", snacks.picker.gh_pr, { desc = "GitHub Pull Requests" })
+vim.keymap.set("n", "<leader>fs", snacks.picker.lsp_symbols, { desc = "Symbols" })
+vim.keymap.set("n", "<leader>fu", snacks.picker.undo, { desc = "Undo History" })
+vim.keymap.set("n", "gI", snacks.picker.lsp_implementations, { desc = "LSP Implementations" })
+vim.keymap.set("n", "gi", snacks.picker.lsp_incoming_calls, { desc = "LSP Incoming Calls" })
+vim.keymap.set("n", "go", snacks.picker.lsp_outgoing_calls, { desc = "LSP Outgoing Calls" })
+vim.keymap.set("n", "gr", snacks.picker.lsp_references, { desc = "LSP References" })
+vim.keymap.set("n", [[<c-\>]], function() snacks.terminal() end, { desc = "Toggle Terminal" })