✨ Language-Aware Automatic Indentation

检查 issue 中描述的当前编辑器缩进行为，然后比较 TextMate 对语言语法的处理方式与所引用的 VSCode 行为。完成标准是：自动缩进和反缩进遵循活动语言语法，可按语言配置，可以禁用，并保留手动缩进控制。

Description

It would be great if CodeEdit, given instructions from the language grammar in use for the open file, were able to automatically indent and outdent lines as you type based on accepted style standards. For example, an "if" statement, "for" loop, etc. in most languages would cause the following lines to be indented once, then the closing bracket or statement would be outdented to line up with the original "if" or "for" statement. This functionality should be adjustable by editing settings for the language and able to be disabled entirely for those that prefer manual indentation.

TextMate is a good example to look at for reasonable behavior. The language grammars it uses to handle this functionality are also plist files and very easy to read to see how it's being done. Some plugins also enable this behavior in VSCode, though it's implemented inconsistently there.

Alternatives Considered

Most editors use manual indentation, which I assume CodeEdit will eventually support. Right now it only supports tabbing in (and does at least maintain that indent), but you cannot shift+tab out or use command+[ or command+] to outdent/indent (respectively) lines or selected blocks. Manual indentation works, and should be an option for those who wish to indent in ways inconsistent with language standards, but is far slower than automatic indentation.

Additional Context

No response

Screenshots

Here's an example of TextMate auto-indenting and outdenting a for loop in a shell script (bash). The second line is automatically indented to my configured tab stop, then once I finish typing "done" it outdents it to match for. This also works correctly if "do" is placed on its own line.

https://github.com/user-attachments/assets/76d5a013-7428-4764-8357-e5bdb6b179c8