[BUG] Leftover [No Name] tab after diff resolve with open_in_new_tab and terminal.provider = none

[phorn1]

Bug Description

When using open_in_new_tab = true combined with terminal.provider = "none" (running Claude Code in an external terminal), resolving a diff (both accept AND reject) leaves behind an empty [No Name] tab. The tab is never cleaned up automatically. Each resolved diff adds another [No Name] tab.

To Reproduce

1. Configure claudecode.nvim:

{
  "coder/claudecode.nvim",
  opts = {
    terminal = { provider = "none" },
    diff_opts = { open_in_new_tab = true },
  },
}

2. Run Claude Code in a separate terminal, connect to Neovim via /ide
3. Have Claude propose a file edit (a diff tab opens)
4. Accept or reject the diff
5. Observe: the diff tab remains as an empty [No Name] tab

Expected Behavior

The diff tab should be fully closed after resolution, returning the user to the original tab.

Root Cause Analysis

_cleanup_diff_state() contains tab-closing logic (lines 1007-1028 in diff.lua) which switches to the new tab and runs tabclose, but wrapped in pcall — errors are silently swallowed. With terminal.provider = "none" there is no terminal buffer, so display_terminal_in_new_tab() takes the early-return path (line 219-222), creating a bare tabnew with only an empty buffer. The tab cleanup appears to fail silently in this scenario.

Multiple workaround attempts from user config (autocommands on TabEnter/TabClosed/BufEnter, monkey-patching _resolve_diff_as_rejected/deny_current_diff) were all unsuccessful.

Environment

• Neovim version: 0.11
• Claude Code CLI version: latest
• OS: macOS (Darwin 25.3.0)
• Plugin version: latest from lazy.nvim

[phorn1]

Related to #155 which was fixed by #175. However, that fix addresses leftover splits in the current tab. This issue is specifically about the open_in_new_tab = true + terminal.provider = "none" combination, where the entire tab remains as [No Name] after diff resolution (both accept and reject). The plugin is on the latest commit (432121f) which includes the #175 fix.

[ldelossa]

Can confirm, I use this plugin like that. We start collecting empty buffers on every new diff tab.