[FEATURE] Add /update-md command

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

It took me a minute to know that init does have an option to update.md considering its current content, but I think that the command /init is kind of an awkward name for this function and throws customers off.

Proposed Solution

I suggest adding another command /update or something similar that does what /init does. but instead, in looks into the current claude.md file and the current files in the project and updates claude.md. I know that if you run /init it would ask if you want to do that (Option 2). but for my confidence, it seems that this is a good option. Also the old claude.md file would be stored in another file name "claude.md.old for example jsut in case I want to revert. claude should keep only one claude.md.old file at a time.

Alternative Solutions

Maybe autoupdate md after each prompt, but customers might not like this for every scenario, unless there is an option for each project to indicate whether the customer wants to do this or not.

Priority

Low - Nice to have

Feature Category

CLI commands and flags

Use Case Example

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Additional Context

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