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/lsp/svelte.lua

@@ -0,0 +1,10 @@
+vim.lsp.config("svelte", {
+  on_attach = function(client, _)
+    vim.api.nvim_create_autocmd("BufWritePost", {
+      pattern = { "*.js", "*.ts" },
+      callback = function(ctx)
+        client.notify("$/onDidChangeTsOrJsFile", { uri = ctx.match })
+      end,
+    })
+  end,
+})