[neovim] replace neo-tree with snacks.nvim

Replace neo-tree.nvim with snacks.nvim for file explorer functionality and
remove several other plugins including:
- mini-animate
- mini-starter
- indent-blankline

The snacks.nvim plugin provides better file explorer, dashboard, indentation
guides, and other UI improvements in a more cohesive package.

Also removed the large file autocommand as snacks.nvim handles this with its
bigfile module.

.config/nvim/lua/core/autocommands.lua

@@ -68,26 +68,3 @@ vim.api.nvim_create_autocmd("FileType", {
 	pattern = { "hcl", "helm" },
 	command = "setlocal shiftwidth=2 tabstop=2",
 })
-
--- Disable some plugins on very large files
-vim.api.nvim_create_autocmd({ "BufEnter" }, {
-	pattern = { "*" },
-	callback = function(args)
-		local highlighter = require("vim.treesitter.highlighter")
-		local ts_was_active = highlighter.active[args.buf]
-		local file_size = vim.fn.getfsize(args.file)
-		if file_size > 1024 * 1024 then
-			vim.cmd("TSBufDisable highlight")
-			vim.cmd("syntax off")
-			vim.cmd("syntax clear")
-			vim.cmd("IlluminatePauseBuf")
-			vim.cmd("NoMatchParen")
-			vim.cmd("UfoDisable")
-			vim.cmd("IBLDisable")
-			vim.cmd("LspStop")
-			if ts_was_active then
-				vim.notify("File larger than 1MB; syntax highlighting and heavy CPU use plugins are turned off.")
-			end
-		end
-	end,
-})