@constraint Annotation for types/aliases

I was working with Annotations for documenting my code and wanted to add a warning if the user used a function that didn't fall under a specific pattern ("0x%x%x%x%x%x%x%x%x") and tried finding a workaround. I'm not 100% fluent with .lua and don't have the confidence to PR, so take my idea instead.

My idea for the annotation would be as follows:

--- @constraint con_color (string.find(T , "^0x%x%x%x%x%x%x%x%x$") or string.find(T , "^%x%x%x%x%x%x$"))
--- @alias color string<con_color>
--- @param col1 color
--- @param col2 color
local function set_col(col1, col2)
    ...
end

Obviously syntax could use work, but the basic idea would be to add a constraint, and have T or whatever variable name be the entry. This way you can give a warning to users about unsupported string or a number being too low/high being used. If there is already something like this please enlighten me as I couldn't find anything

首先檢查 language server 現有的 @alias 和 @param 註解處理，因為 issue 沒有指定具體的檔案或測試。確定提議的 @constraint 語法如何驗證別名並產生警告，然後在實作之前定義語法和預期行為；完成意味著已記錄的約束對顏色範例有效，並且能夠診斷無效值。