refactor: revert module namespace from canola back to oil

Problem: the canola rename creates unnecessary friction for users
migrating from stevearc/oil.nvim — every `require('oil')` call and
config reference must change.

Solution: revert all module paths, URL schemes, autocmd groups,
highlight groups, and filetype names back to `oil`. The repo stays
`canola.nvim` for identity; the code is a drop-in replacement.

lua/oil/mutator/confirmation.lua

@@ -0,0 +1,205 @@
+local columns = require('oil.columns')
+local config = require('oil.config')
+local layout = require('oil.layout')
+local util = require('oil.util')
+local M = {}
+
+---@param actions oil.Action[]
+---@return boolean
+local function is_simple_edit(actions)
+  local num_create = 0
+  local num_copy = 0
+  local num_move = 0
+  for _, action in ipairs(actions) do
+    -- If there are any deletes, it is not a simple edit
+    if action.type == 'delete' then
+      return false
+    elseif action.type == 'create' then
+      num_create = num_create + 1
+    elseif action.type == 'copy' then
+      num_copy = num_copy + 1
+      -- Cross-adapter copies are not simple
+      if util.parse_url(action.src_url) ~= util.parse_url(action.dest_url) then
+        return false
+      end
+    elseif action.type == 'move' then
+      num_move = num_move + 1
+      -- Cross-adapter moves are not simple
+      if util.parse_url(action.src_url) ~= util.parse_url(action.dest_url) then
+        return false
+      end
+    end
+  end
+  -- More than one move/copy is complex
+  if num_move > 1 or num_copy > 1 then
+    return false
+  end
+  -- More than 5 creates is complex
+  if num_create > 5 then
+    return false
+  end
+  return true
+end
+
+---@param winid integer
+---@param bufnr integer
+---@param lines string[]
+local function render_lines(winid, bufnr, lines)
+  util.render_text(bufnr, lines, {
+    v_align = 'top',
+    h_align = 'left',
+    winid = winid,
+    actions = { '[Y]es', '[N]o' },
+  })
+end
+
+---@param actions oil.Action[]
+---@param should_confirm nil|boolean
+---@param cb fun(proceed: boolean)
+M.show = vim.schedule_wrap(function(actions, should_confirm, cb)
+  -- The schedule wrap ensures that we actually enter the floating window.
+  -- Not sure why it doesn't work without that
+  if should_confirm == false or #actions == 0 then
+    cb(true)
+    return
+  end
+  if should_confirm == nil and config.skip_confirm_for_simple_edits and is_simple_edit(actions) then
+    cb(true)
+    return
+  end
+  if should_confirm == nil and config.skip_confirm_for_delete then
+    local all_deletes = true
+    for _, action in ipairs(actions) do
+      if action.type ~= 'delete' then
+        all_deletes = false
+        break
+      end
+    end
+    if all_deletes then
+      cb(true)
+      return
+    end
+  end
+
+  -- Create the buffer
+  local bufnr = vim.api.nvim_create_buf(false, true)
+  vim.bo[bufnr].bufhidden = 'wipe'
+  local lines = {}
+  local max_line_width = 0
+  for _, action in ipairs(actions) do
+    local adapter = util.get_adapter_for_action(action)
+    local line
+    if action.type == 'change' then
+      ---@cast action oil.ChangeAction
+      line = columns.render_change_action(adapter, action)
+    else
+      line = adapter.render_action(action)
+    end
+    -- We can't handle lines with newlines in them
+    line = line:gsub('\n', '')
+    table.insert(lines, line)
+    local line_width = vim.api.nvim_strwidth(line)
+    if line_width > max_line_width then
+      max_line_width = line_width
+    end
+  end
+  table.insert(lines, '')
+
+  -- Create the floating window
+  local width, height = layout.calculate_dims(max_line_width, #lines + 1, config.confirmation)
+  local ok, winid = pcall(vim.api.nvim_open_win, bufnr, true, {
+    relative = 'editor',
+    width = width,
+    height = height,
+    row = math.floor((layout.get_editor_height() - height) / 2),
+    col = math.floor((layout.get_editor_width() - width) / 2),
+    zindex = 152, -- render on top of the floating window title
+    style = 'minimal',
+    border = config.confirmation.border,
+  })
+  if not ok then
+    vim.notify(string.format('Error showing oil preview window: %s', winid), vim.log.levels.ERROR)
+    cb(false)
+  end
+  vim.bo[bufnr].filetype = 'oil_preview'
+  vim.bo[bufnr].syntax = 'oil_preview'
+  for k, v in pairs(config.confirmation.win_options) do
+    vim.api.nvim_set_option_value(k, v, { scope = 'local', win = winid })
+  end
+
+  render_lines(winid, bufnr, lines)
+
+  local restore_cursor = util.hide_cursor()
+
+  -- Attach autocmds and keymaps
+  local cancel
+  local confirm
+  local autocmds = {}
+  local function make_callback(value)
+    return function()
+      confirm = function() end
+      cancel = function() end
+      for _, id in ipairs(autocmds) do
+        vim.api.nvim_del_autocmd(id)
+      end
+      autocmds = {}
+      vim.api.nvim_win_close(winid, true)
+      restore_cursor()
+      cb(value)
+    end
+  end
+  cancel = make_callback(false)
+  confirm = make_callback(true)
+  vim.api.nvim_create_autocmd('BufLeave', {
+    callback = function()
+      cancel()
+    end,
+    once = true,
+    nested = true,
+    buffer = bufnr,
+  })
+  vim.api.nvim_create_autocmd('WinLeave', {
+    callback = function()
+      cancel()
+    end,
+    once = true,
+    nested = true,
+  })
+  table.insert(
+    autocmds,
+    vim.api.nvim_create_autocmd('VimResized', {
+      callback = function()
+        if vim.api.nvim_win_is_valid(winid) then
+          width, height = layout.calculate_dims(max_line_width, #lines, config.confirmation)
+          vim.api.nvim_win_set_config(winid, {
+            relative = 'editor',
+            width = width,
+            height = height,
+            row = math.floor((layout.get_editor_height() - height) / 2),
+            col = math.floor((layout.get_editor_width() - width) / 2),
+            zindex = 152, -- render on top of the floating window title
+          })
+          render_lines(winid, bufnr, lines)
+        end
+      end,
+    })
+  )
+
+  -- We used to use [C]ancel to cancel, so preserve the old keymap
+  local cancel_keys = { 'n', 'N', 'c', 'C', 'q', '<C-c>', '<Esc>' }
+  for _, cancel_key in ipairs(cancel_keys) do
+    vim.keymap.set('n', cancel_key, function()
+      cancel()
+    end, { buffer = bufnr, nowait = true })
+  end
+
+  -- We used to use [O]k to confirm, so preserve the old keymap
+  local confirm_keys = { 'y', 'Y', 'o', 'O' }
+  for _, confirm_key in ipairs(confirm_keys) do
+    vim.keymap.set('n', confirm_key, function()
+      confirm()
+    end, { buffer = bufnr, nowait = true })
+  end
+end)
+
+return M