refactor: switch to catppuccin mocha across tmux and neovim

- tmux: hand-rolled catppuccin theme, three-way status bar toggle, plugin cleanup
- nvim: switch colorscheme to catppuccin-mocha, update lualine colors
- nvim: add tmuxline.vim for tmux statusline generation
- kitty: fix MesloLGS NF font typo, remove deprecated config keys

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nvim/lua/settings.lua

@@ -1,19 +1,19 @@
 -- Global settings
-vim.opt.tabstop = 4 -- Number of spaces that a <Tab> counts for
-vim.opt.shiftwidth = 4 -- Number of spaces for indentation
-vim.opt.expandtab = true -- Use spaces instead of tabs
-vim.opt.cmdheight = 0 -- Hide command line when not in use
+vim.opt.tabstop = 4                               -- Number of spaces that a <Tab> counts for
+vim.opt.shiftwidth = 4                            -- Number of spaces for indentation
+vim.opt.expandtab = true                          -- Use spaces instead of tabs
+vim.opt.cmdheight = 0                             -- Hide command line when not in use
 
-vim.cmd([[highlight CursorLine guibg=#3c3836]]) -- Darker background for the line
-vim.cmd([[highlight CursorColumn guibg=#504945]]) -- Slightly darker for the column
+vim.cmd([[highlight CursorLine guibg=#313244]])   -- Catppuccin surface0
+vim.cmd([[highlight CursorColumn guibg=#45475a]]) -- Catppuccin surface1
 
-vim.cmd([[set incsearch ]]) -- Enables incremental search
-vim.cmd([[set hlsearch  ]]) -- Highlights search results
-vim.cmd([[set ignorecase]]) -- Case insensitive search
-vim.cmd([[set smartcase ]]) -- Case sensitive if uppercase letters are used
+vim.cmd([[set incsearch ]])                       -- Enables incremental search
+vim.cmd([[set hlsearch  ]])                       -- Highlights search results
+vim.cmd([[set ignorecase]])                       -- Case insensitive search
+vim.cmd([[set smartcase ]])                       -- Case sensitive if uppercase letters are used
 
--- Coloscheme
-vim.cmd([[colorscheme gruvbox]])
+-- Colorscheme
+vim.cmd([[colorscheme catppuccin-mocha]])
 
 vim.cmd([[set spelllang=en]])
 
@@ -26,10 +26,10 @@ vim.o.title = true
 vim.o.titlestring = "nvim: %f"
 
 vim.api.nvim_create_autocmd("FileType", {
-	pattern = "lua",
-	callback = function()
-		vim.opt_local.foldmethod = "marker"
-		vim.opt_local.foldlevel = 99 -- so folds are open by default
-		vim.opt_local.fileencoding = "utf-8"
-	end,
+    pattern = "lua",
+    callback = function()
+        vim.opt_local.foldmethod = "marker"
+        vim.opt_local.foldlevel = 99 -- so folds are open by default
+        vim.opt_local.fileencoding = "utf-8"
+    end,
 })