vibe uninstall only checks current shell rc file

[iamnotstatic]

`vibe uninstall` uses `detectShell()` which picks a single rc file based on `$SHELL`. If a user ran `vibe init` under zsh then later switched their default shell to bash (or vice versa), the hooks in the old rc file are left behind.

Expected behavior

`vibe uninstall` should check both `/.zshrc` and `/.bashrc` and remove hooks from any file that contains them.

Current behavior

Only the rc file matching `$SHELL` is cleaned up.

Notes

• `vibe init` has the same single-shell assumption, but it's less of a problem there since the user is actively choosing to set up the current shell.
• Fish is not supported (tracked in Fish shell not supported #1), so this only applies to bash/zsh.