fix(nvim): pass Esc through to an nvim nested in a workspace terminal

[baairon]

Problem

Running Claude Code's /plan open (or git commit, or any other program that starts $EDITOR) in a workspace terminal starts a second nvim inside that pane. The terminal's <Esc><Esc> mapping belongs to the outer nvim, so a double Esc typed in the nested nvim switched the outer nvim out of terminal mode. The :q / :wq that followed then went to the outer nvim:

• :q closed the terminal pane's window, so the pane looked wiped and blank. The nested nvim kept running in the hidden terminal buffer.
• :wq failed with E382: Cannot write, 'buftype' option is set.

When that hidden nvim was eventually killed, Claude Code reported Nvim quit unexpectedly (exit code 1).

I reproduced this on Linux by running your config in tmux, with a nested nvim inside a workspace bash terminal.

Fix

New module nvim/lua/config/workspace/nested.lua, set up from layout.lua:

• Nested side: on UIEnter, an nvim whose $NVIM names another nvim connects to it and reports in. On VimLeavePre it reports that it is leaving.
• Outer side: the terminal buffer the nested nvim reported from gets a buffer-local nowait <Esc> that goes straight through to the nested nvim, with no timeoutlen delay. When the nested nvim leaves, that mapping is removed and <Esc><Esc> works as before. If the nested nvim dies without reporting, the next Esc finds its channel gone and removes the mapping.
• The Alt chords still reach the outer nvim, so moving between panes works the same while the nested nvim is open.
• Only a terminal buffer can be marked. An nvim whose $NVIM is stale or points somewhere else does nothing.

Testing

• In the tmux repro: typing text, double Esc, then :wq in the nested nvim now saves the file and exits 0. The pane stays, <Esc><Esc> leaves terminal mode again afterwards, and after a kill -9 of the nested nvim the mapping is removed on the next Esc.
• Added checks to tests/runtime.lua. nvim --headless -u NONE -l tests/runtime.lua passes all 300 checks.
• Not tested on Windows, where ConPTY and named pipes are used.

🤖 Generated with Claude Code

https://claude.ai/code/session_01Pr6jVTWbDwEJ4p8ZANoqzs

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Generated by Claude Code