Remove or fix arbitrary 10MB size check for binary validation

Problem

The /status command validates binaries by checking if they're >10MB, which incorrectly flags wrapper scripts as invalid.

Question

Is this size validation necessary at all? The 10MB threshold seems arbitrary and causes false positives.

Better Alternatives

Instead of checking size, consider:

1. Check if executable (simplest):

fs.accessSync(path, fs.constants.X_OK)

1. No validation - If the symlink exists and points somewhere, that's probably enough

1. Actually test it - Try running claude --version to verify it works

The current size check doesn't actually validate anything meaningful - small executables are perfectly valid, and large non-executables would incorrectly pass.

This affects Nix, potentially Homebrew, and any package manager using wrapper scripts.