nvim,tmux,kitty: full config overhaul (AstroNvim → native 0.12)

Replaces AstroNvim v5 with from-scratch Neovim 0.12 config using
vim.lsp.config()/vim.lsp.enable() natively, lazy.nvim, blink.cmp,
and smart-splits tmux integration.

tmux: new C-Space prefix, hjkl pane nav, resize key table, tpm plugins.
kitty: add allow_remote_control for smart-splits.

dot_config/nvim/lua/plugins/none-ls.lua

@@ -1,24 +1,2 @@
-if true then return {} end -- WARN: REMOVE THIS LINE TO ACTIVATE THIS FILE
-
--- Customize None-ls sources
-
----@type LazySpec
-return {
-  "nvimtools/none-ls.nvim",
-  opts = function(_, opts)
-    -- opts variable is the default configuration table for the setup function call
-    -- local null_ls = require "null-ls"
-
-    -- Check supported formatters and linters
-    -- https://github.com/nvimtools/none-ls.nvim/tree/main/lua/null-ls/builtins/formatting
-    -- https://github.com/nvimtools/none-ls.nvim/tree/main/lua/null-ls/builtins/diagnostics
-
-    -- Only insert new sources, do not replace the existing ones
-    -- (If you wish to replace, use `opts.sources = {}` instead of the `list_insert_unique` function)
-    opts.sources = require("astrocore").list_insert_unique(opts.sources, {
-      -- Set a formatter
-      -- null_ls.builtins.formatting.stylua,
-      -- null_ls.builtins.formatting.prettier,
-    })
-  end,
-}
+-- none-ls replaced by conform.nvim in editing.lua
+return {}