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/autocmds.lua

@@ -0,0 +1,81 @@
+local augroup = function(name)
+  return vim.api.nvim_create_augroup("user_" .. name, { clear = true })
+end
+
+-- Filetype detection
+vim.filetype.add({ extension = { j2 = "jinja.html" } })
+
+-- Highlight on yank
+vim.api.nvim_create_autocmd("TextYankPost", {
+  group = augroup("yank_highlight"),
+  callback = function()
+    vim.highlight.on_yank()
+  end,
+})
+
+-- Remove trailing whitespace on save
+vim.api.nvim_create_autocmd("BufWritePre", {
+  group = augroup("trailing_whitespace"),
+  pattern = "*",
+  command = [[%s/\s\+$//e]],
+})
+
+-- Resize splits when window resizes
+vim.api.nvim_create_autocmd("VimResized", {
+  group = augroup("resize_splits"),
+  callback = function()
+    local current_tab = vim.fn.tabpagenr()
+    vim.cmd("tabdo wincmd =")
+    vim.cmd("tabnext " .. current_tab)
+  end,
+})
+
+-- Close certain filetypes with q
+vim.api.nvim_create_autocmd("FileType", {
+  group = augroup("close_with_q"),
+  pattern = { "help", "lspinfo", "man", "qf", "checkhealth" },
+  callback = function(event)
+    vim.bo[event.buf].buflisted = false
+    vim.keymap.set("n", "q", "<cmd>close<cr>", { buffer = event.buf, silent = true })
+  end,
+})
+
+-- LSP on attach: inlay hints + navic
+vim.api.nvim_create_autocmd("LspAttach", {
+  group = augroup("lsp_attach"),
+  callback = function(args)
+    local client = vim.lsp.get_client_by_id(args.data.client_id)
+    if not client then return end
+
+    -- Enable inlay hints
+    if client.supports_method("textDocument/inlayHint") then
+      vim.lsp.inlay_hint.enable(true, { bufnr = args.buf })
+    end
+
+    -- Wire nvim-navic for breadcrumbs (lualine winbar)
+    if client.supports_method("textDocument/documentSymbol") then
+      local ok, navic = pcall(require, "nvim-navic")
+      if ok then
+        navic.attach(client, args.buf)
+      end
+    end
+
+    -- LSP keymaps (buffer-local)
+    local map = function(keys, func, desc)
+      vim.keymap.set("n", keys, func, { buffer = args.buf, desc = "LSP: " .. desc })
+    end
+
+    map("gd", vim.lsp.buf.definition,      "Go to definition")
+    map("gi", vim.lsp.buf.implementation,  "Go to implementation")
+    map("<leader>D", vim.lsp.buf.type_definition, "Type definition")
+    map("<leader>lf", function() vim.lsp.buf.format({ async = true }) end, "Format")
+    map("<leader>lr", vim.lsp.buf.rename,  "Rename symbol")
+    map("<leader>ls", vim.lsp.buf.document_symbol, "Document symbols")
+    map("<leader>lR", vim.lsp.buf.references, "References")
+    map("<leader>li", function()
+      vim.lsp.inlay_hint.enable(not vim.lsp.inlay_hint.is_enabled({ bufnr = args.buf }), { bufnr = args.buf })
+    end, "Toggle inlay hints")
+
+    -- grr, grn, gra, K are Neovim 0.12 built-ins, no need to set
+  end,
+})