feat(nvim): auto-quit when only NERDTree/dadbod/Claude Code remain

After closing the file you were working on, if every remaining window
in the (only) tab is NERDTree, the dadbod-ui browser, or the Claude
Code terminal, there's nothing left to edit — a WinClosed autocmd
force-quits (qa!) rather than leaving you staring at bare utility
sidebars. qa! also bypasses the "terminal job still running" prompt
for the live Claude Code process; nothing there is a real file buffer.

Verified live: closing a file while another real file window remains
does not quit; closing the last real file with only utility windows
left (individually tested with NERDTree, dadbod-ui, and a
claude-named terminal buffer) does.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/md/editors.md

@@ -97,6 +97,12 @@ Claude Code can write files outside `claudecode.nvim`'s diff-review pipeline (pl
 
 Unmodified buffers reload silently; buffers with unsaved local edits still get Vim's normal "changed outside Vim" (`W11`) prompt instead of being clobbered.
 
+### Auto-Quit When Only Utility Windows Remain
+
+A `WinClosed` autocmd checks, after every window close, whether every window left in the (only) tab is one of NERDTree, the dadbod-ui browser, or the Claude Code terminal. If so — nothing left to edit — it runs `:qa!` outright, including skipping the "terminal job still running" confirmation that would otherwise block quitting while Claude Code's process is alive.
+
+Scoped to just those three; a real file window anywhere in the tab (or a second tab) always blocks the auto-quit.
+
 ### Keybindings
 
 All custom bindings live in `nvim/init.lua`. Leader is `<Space>` (`vim.g.mapleader = " "`) — Space otherwise duplicates `l` (move right) in normal mode, so it was free to claim.

nvim/init.lua

@@ -191,6 +191,39 @@ vim.api.nvim_create_autocmd("User", {
     command = "checktime",
 })
 
+-- quit outright once only plugin/utility windows remain ─────────────────────
+-- After closing the file you were working on, if NERDTree, the dadbod-ui
+-- browser, and/or the Claude Code terminal are the only windows left in the
+-- (only) tab, there's nothing left to edit. qa! also skips the "terminal job
+-- still running" confirmation for the Claude Code process; nothing here is a
+-- real file buffer, so there's nothing to lose.
+local function _is_utility_win(win)
+    local buf = vim.api.nvim_win_get_buf(win)
+    local ft  = vim.bo[buf].filetype
+    if ft == "nerdtree" or ft == "dbui" then
+        return true
+    end
+    if vim.bo[buf].buftype == "terminal" then
+        return vim.api.nvim_buf_get_name(buf):match("claude") ~= nil
+    end
+    return false
+end
+
+vim.api.nvim_create_autocmd("WinClosed", {
+    callback = function()
+        -- defer: the closed window is still mid-teardown when WinClosed fires
+        vim.schedule(function()
+            if vim.fn.tabpagenr("$") > 1 then return end
+            local wins = vim.api.nvim_tabpage_list_wins(0)
+            if #wins == 0 then return end
+            for _, w in ipairs(wins) do
+                if not _is_utility_win(w) then return end
+            end
+            vim.cmd("qa!")
+        end)
+    end,
+})
+
 -- calendar.vim steals <C-hjkl> for month nav; restore window movement
 -- The plugin sets buffer-local mappings on FileType calendar, so we override
 -- them with { buffer = true } mappings of our own that fire after the plugin's.