feat: implement single project truncation command

[guidodinello]

Add support for single project truncation

Problem

The current truncate command only supports batch deletion of files from all projects at once. This can be overwhelming and risky when working with projects containing hundreds of files, as users often need to manage files for specific projects individually.

Solution

Modified the truncate command to:

• Default to single project truncation with interactive selection
• Maintain batch truncation capability via --all flag

Usage

Single Project (New Default):

claudesync project truncate

[jahwag]

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[jahwag]

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