nvim-lint triggers a full lint run on BufEnter — linters spawn on every buffer switch

[ooloth]

Current state

lua/config/plugins/specs/nvim-lint.lua registers lint.try_lint() on both BufEnter and BufWritePost. BufEnter fires every time the user switches to any buffer — including switching windows, opening help pages, and navigating the file tree — causing a full lint process to spawn on each transition regardless of whether the buffer's content has changed.

Ideal state

• Linting is triggered only on BufWritePost (and optionally InsertLeave for a real-time feel after leaving insert mode).
• BufEnter is removed from the autocmd event list.
• No lint processes are spawned when the user switches windows or opens a non-editable buffer.

Starting points

• lua/config/plugins/specs/nvim-lint.lua — the autocmd registration listing BufEnter alongside BufWritePost

QA plan

1. Open lua/config/plugins/specs/nvim-lint.lua. Expect to see BufEnter in the autocmd event list passed to nvim_create_autocmd.
2. After the fix, read the file. Expect BufEnter to be absent; BufWritePost (and optionally InsertLeave) remain.
3. Start Neovim, open a linted file, and switch to another window. Expect no linter process to be spawned (observable via :lua print(vim.inspect(require('lint').get_running())) returning an empty table immediately after the switch).
4. Save the linted file. Expect lint.try_lint() to run and diagnostics to appear normally.

Done when

lint.try_lint() is not invoked when the user switches buffers or windows — only after a file save (and optionally after leaving insert mode).