feat: improve portability and add Grug-far QoL improvements

- Refactor terminal title logic in lua/options.lua with Kitty detection and OSC 2 fallback.
- Set mapleader and maplocalleader explicitly at the top of lua/options.lua.
- Add <leader>sr mapping for Grug-far search and replace in lua/keymaps.lua.
- Add autocommand to close Grug-far window with 'q'.
- Update README.md with system dependencies (Debian/Arch) and new keymaps.
- Highlight portability features (terminal titles, root detection) in README.md.

lua/options.lua

@@ -4,6 +4,10 @@
   └────────────────────────────────────────────────────────────────┘
 --]]
 
+-- Set leader keys before any other configuration
+vim.g.mapleader = " "
+vim.g.maplocalleader = "\\"
+
 -- Copyright (C) 2026 rootiest
 --
 -- This program is free software: you can redistribute it and/or modify
@@ -66,3 +70,107 @@ vim.api.nvim_create_user_command("Format", function(args)
 	end
 	require("conform").format({ async = true, lsp_format = "fallback", range = range })
 end, { range = true })
+
+--[[
+  ┌────────────────────────────────────────────────────────────────┐
+  │                        Root Management                         │
+  └────────────────────────────────────────────────────────────────┘
+--]]
+
+-- Automatically change the working directory to the project root.
+-- This ensures that plugins like Snacks.picker and GrugFar work
+-- relative to the file or project you are currently editing.
+vim.api.nvim_create_autocmd("BufEnter", {
+	group = vim.api.nvim_create_augroup("rootiest_auto_cd", { clear = true }),
+	callback = function()
+		local path = vim.api.nvim_buf_get_name(0)
+		if path == "" then
+			return
+		end
+
+		-- Skip special buffers, but allow directory buffers (for explorer support)
+		if vim.bo.buftype ~= "" and vim.bo.filetype ~= "snacks_explorer_tree" then
+			return
+		end
+
+		-- Get the directory (handle both files and directory paths)
+		local dir = vim.fn.isdirectory(path) == 1 and path or vim.fn.fnamemodify(path, ":p:h")
+
+		-- Find the project root using common markers, fallback to the directory itself
+		local root = vim.fs.root(dir, { ".git", "lua", "package.json", "go.mod", "Cargo.toml", "Makefile" }) or dir
+
+		-- Change directory if it's different and valid
+		if root and vim.fn.isdirectory(root) == 1 and root ~= vim.fn.getcwd() then
+			vim.fn.chdir(root)
+		end
+	end,
+})
+
+-- Grug-far QoL: Close with 'q'
+vim.api.nvim_create_autocmd("FileType", {
+	group = vim.api.nvim_create_augroup("grug_far_q_to_close", { clear = true }),
+	pattern = "grug-far",
+	callback = function(args)
+		vim.keymap.set("n", "q", "<cmd>close<cr>", { buffer = args.buf, silent = true, desc = "Close Grug-far" })
+	end,
+})
+
+--[[
+  ┌────────────────────────────────────────────────────────────────┐
+  │                       Shell Interaction                        │
+  └────────────────────────────────────────────────────────────────┘
+--]]
+
+-- Detect terminal environment
+local is_kitty = os.getenv("KITTY_PID") ~= nil
+local current_shell = os.getenv("SHELL") or "/bin/sh"
+local shell_name = current_shell:match("([^/]+)$") or "sh"
+
+-- Helper function to update the terminal title
+local function set_terminal_title(title)
+	-- If in Kitty, we use the direct escape sequence as it's reliable
+	if is_kitty then
+		io.stdout:write("\27]2;" .. title .. "\7")
+	-- Fallback: Use Neovim's built-in title management for other terminals
+	-- (Standard OSC 2 sequences are supported by most, but opt.title is safer)
+	elseif os.getenv("TERM") ~= "linux" then
+		vim.opt.title = true
+		vim.opt.titlestring = title
+	end
+end
+
+-- Create the Autocommand Group
+local title_group = vim.api.nvim_create_augroup("TerminalTitle", { clear = true })
+
+vim.api.nvim_create_autocmd({ "BufEnter", "BufWinEnter" }, {
+	group = title_group,
+	callback = function()
+		local buftype = vim.bo.buftype
+		local filetype = vim.bo.filetype
+		local filename = vim.fn.expand("%:t")
+
+		-- 1. Specifically catch Snacks Terminal or standard Terminals
+		if filetype == "snacks_terminal" or buftype == "terminal" then
+			set_terminal_title("NVIM: Terminal")
+
+		-- 2. Handle normal files (buftype is empty)
+		elseif buftype == "" and filename ~= "" then
+			set_terminal_title("NVIM: " .. filename)
+
+		-- 3. Handle the empty start screen
+		elseif filename == "" and buftype == "" then
+			set_terminal_title("Neovim")
+		end
+	end,
+})
+
+-- Reset the title back to the shell name when you quit Neovim
+vim.api.nvim_create_autocmd("VimLeave", {
+	group = title_group,
+	callback = function()
+		-- On leave, direct stdout is more reliable than setting an option
+		if is_kitty or os.getenv("TERM") ~= "linux" then
+			io.stdout:write("\27]2;" .. shell_name .. "\7")
+		end
+	end,
+})