feat: add terminal buffers to selected files (#2077)

Co-authored-by: Samuel Wall <me@samuelwall.uk>

lua/avante/utils/init.lua

@@ -1094,7 +1094,7 @@ end
 ---@return string[]|nil lines
 ---@return string|nil error
 function M.read_file_from_buf_or_disk(filepath)
-  local abs_path = M.join_paths(M.get_project_root(), filepath)
+  local abs_path = filepath:sub(1, 7) == "term://" and filepath or M.join_paths(M.get_project_root(), filepath)
   --- Lookup if the file is loaded in a buffer
   local bufnr = vim.fn.bufnr(abs_path)
   if bufnr ~= -1 and vim.api.nvim_buf_is_loaded(bufnr) then