fix(bundle): avoid eval in --prefix handling

[isuzano]

This patch removes the use of eval from --prefix handling in bin/bundle.sh
and replaces it with minimal explicit ~ expansion.

It also fixes a few small quoting issues involving:

• "$@"
• cp "$1" "$2"

Scope intentionally kept minimal:

• no allocator/core changes
• no build system changes
• no behavioral refactors

[daanx]

Thank you!