refactor & fix: improve libraries initialization (#921)

* refactor(libs): extract libraries initialization

Extract initialization logic into separate functions
for better error handling and reusability.

* fix(libs): improve core libraries init

This change helps prevent runtime errors from uninitialized libraries.

lua/avante/repo_map.lua

@@ -15,16 +15,23 @@ local repo_map_lib = nil
 ---@class avante.utils.repo_map
 local RepoMap = {}
 
-function RepoMap.setup()
-  vim.defer_fn(function()
-    local ok, core = pcall(require, "avante_repo_map")
-    if not ok then
-      error("Failed to load avante_repo_map")
-      return
-    end
+---@return AvanteRepoMap|nil
+function RepoMap._init_repo_map_lib()
+  if repo_map_lib ~= nil then
+    return repo_map_lib
+  end
 
-    if repo_map_lib == nil then repo_map_lib = core end
-  end, 1000)
+  local ok, core = pcall(require, "avante_repo_map")
+  if not ok then
+    return nil
+  end
+
+  repo_map_lib = core
+  return repo_map_lib
+end
+
+function RepoMap.setup()
+  vim.defer_fn(RepoMap._init_repo_map_lib, 1000)
 end
 
 function RepoMap.get_ts_lang(filepath)
@@ -51,12 +58,13 @@ function RepoMap._build_repo_map(project_root, file_ext)
   local negate_patterns = vim.list_extend(gitignore_negate_patterns, Config.repo_map.negate_patterns)
 
   local filepaths = Utils.scan_directory(project_root, ignore_patterns, negate_patterns)
+  if filepaths and not RepoMap._init_repo_map_lib() then
+    -- or just throw an error if we don't want to execute request without codebase
+    Utils.error("Failed to load avante_repo_map")
+    return
+  end
   vim.iter(filepaths):each(function(filepath)
     if not Utils.is_same_file_ext(file_ext, filepath) then return end
-    if not repo_map_lib then
-      Utils.error("Failed to load avante_repo_map")
-      return
-    end
     local filetype = RepoMap.get_ts_lang(filepath)
     local definitions = filetype
         and repo_map_lib.stringify_definitions(filetype, Utils.file.read_content(filepath) or "")