@spec check_optional() :: [atom()]

Check which optional dependencies are present in mix.exs.

Returns a list of found optional dependencies.

@spec check_required() :: :ok | {:error, [atom()]}

Check if all required dependencies are present in mix.exs.

Returns :ok if all required deps are found, or {:error, [missing_deps]} if any are missing.

@spec dep_exists?(atom()) :: boolean()

Check if a specific dependency exists in mix.exs.

Returns true if the dependency is found, false otherwise.

@spec missing_deps_message([atom()]) :: String.t()

Generate a friendly error message for missing dependencies.

Returns a formatted string listing the missing dependencies and how to add them.