refactor(git): pull buffer-placement tail into util.place_buf

lua/git/util.lua

@@ -41,6 +41,24 @@ function M.parse_revspec(revspec)
     return { stage = nil, path = path }
 end
 
+---Place a buffer in the current window or a new split per `split`.
+---`false` replaces the current buffer (drops a `'` mark first so `''`
+---jumps back); a direction string opens a leftabove split; nil falls
+---back to a `splitbelow`-aware horizontal split.
+---@param buf integer
+---@param split (false|"above"|"below"|"left"|"right")?
+---@return integer win
+function M.place_buf(buf, split)
+    if split == false then
+        vim.cmd.normal({ "m'", bang = true })
+        vim.api.nvim_set_current_buf(buf)
+        return vim.api.nvim_get_current_win()
+    end
+    return vim.api.nvim_open_win(buf, true, {
+        split = split or (vim.o.splitbelow and "below" or "above"),
+    })
+end
+
 ---@class ow.Git.NewScratchOpts
 ---@field name string?
 ---@field bufhidden ("hide"|"wipe")?  defaults to "hide"
@@ -63,14 +81,7 @@ function M.new_scratch(opts)
     if opts.name then
         pcall(vim.api.nvim_buf_set_name, buf, opts.name)
     end
-    if opts.split == false then
-        vim.cmd.normal({ "m'", bang = true })
-        vim.api.nvim_set_current_buf(buf)
-        return buf, vim.api.nvim_get_current_win()
-    end
-    local split = opts.split or (vim.o.splitbelow and "below" or "above")
-    local win = vim.api.nvim_open_win(buf, true, { split = split })
-    return buf, win
+    return buf, M.place_buf(buf, opts.split)
 end
 
 ---@param fmt string