refactor(plugins): replace neo-tree with yazi as the file manager

lua/plugins/user.lua

@@ -1,53 +1,43 @@
 --- User plugins: cursor animation and snacks.nvim (picker + dashboard) customization
 
--- Confirm action for file-opening pickers:
--- open in a vertical split by default, reuse the window when the buffer is
--- already visible in this tab, plain edit when the main window holds an
--- empty scratch buffer. Explicit edit-cmd keybinds (<c-s> split, <c-v>
--- vsplit, <c-t> tab) carry `action.cmd` and are passed through untouched.
-local function vsplit_confirm(picker, item, action)
+-- Confirm action for file-opening pickers: <CR> opens the selection as a
+-- tab via `tabdrop` (:tab drop semantics — focus the buffer if it's already
+-- visible in any tab, don't spawn a tab from an empty buffer, else open a
+-- new tab). Explicit edit-cmd keybinds (<S-CR>/<c-v> vsplit, <c-s> split)
+-- carry `action.cmd` and are passed through untouched.
+local function tab_confirm(picker, item, action)
   local actions = require "snacks.picker.actions"
   if action.cmd then return actions.jump(picker, item, action) end
-  local path = item and item.file and require("snacks.picker.util").path(item)
-  if not (item and (item.buf or path)) then return actions.jump(picker, item, action) end
-  local buf = item.buf or vim.fn.bufadd(path)
-  local visible = false
-  for _, w in ipairs(vim.fn.win_findbuf(buf)) do
-    if
-      vim.api.nvim_win_get_tabpage(w) == vim.api.nvim_get_current_tabpage()
-      and vim.api.nvim_win_get_config(w).relative == ""
-    then
-      visible = true
-      break
-    end
-  end
-  local main_buf = picker.main and vim.api.nvim_win_is_valid(picker.main) and vim.api.nvim_win_get_buf(picker.main)
-  local main_empty = main_buf
-    and vim.api.nvim_buf_get_name(main_buf) == ""
-    and vim.bo[main_buf].buftype == ""
-    and not vim.bo[main_buf].modified
-  local cmd = (visible or main_empty) and "edit" or "vsplit"
-  return actions.jump(picker, item, vim.tbl_extend("force", {}, action, { cmd = cmd }))
+  return actions.jump(picker, item, vim.tbl_extend("force", {}, action, { cmd = "tabdrop" }))
+end
+
+-- Tab-on-enter + vsplit-on-shift-enter for the file-opening pickers only;
+-- location pickers (lsp_*, lines, diagnostics, grep) and sources with their
+-- own confirm (git_branches, projects) keep their defaults.
+local picker_sources = {}
+for _, source in ipairs { "files", "git_files", "smart", "recent", "buffers" } do
+  picker_sources[source] = {
+    confirm = tab_confirm,
+    win = {
+      input = { keys = { ["<S-CR>"] = { "edit_vsplit", mode = { "n", "i" } } } },
+      list = { keys = { ["<S-CR>"] = "edit_vsplit" } },
+    },
+  }
 end
 
 ---@type LazySpec
 return {
   { "sphamba/smear-cursor.nvim", opts = {} },
 
+  -- terminals are handled by kitty now
+  { "akinsho/toggleterm.nvim", enabled = false },
+
   {
     "folke/snacks.nvim",
     opts = {
       picker = {
         jump = { reuse_win = true },
-        -- vsplit-by-default only for file-opening pickers; location pickers
-        -- (lsp_*, lines, diagnostics, grep) keep the default in-window jump
-        sources = {
-          files = { confirm = vsplit_confirm },
-          git_files = { confirm = vsplit_confirm },
-          smart = { confirm = vsplit_confirm },
-          recent = { confirm = vsplit_confirm },
-          buffers = { confirm = vsplit_confirm },
-        },
+        sources = picker_sources,
       },
       dashboard = {
         enabled = true,