[FEATURE] Support environment variables and path shortcuts in claude settings

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

When configuring allowed commands for Claude (e.g., allowing cat within a specific directory), the path must be written as an absolute path such as:

/home/me/workspace

This causes portability issues.

Proposed Solution

Allow environment variable expansion and path shortcuts in the allowed-path configuration.

Examples:

$HOME/workspace
~/workspace

Alternative Solutions

There are no workarounds.

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

See above.

Additional Context

_No response_