trim down install, tighten sshd

migrations/1793452585.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# ~/.bashrc pointed SSH_AUTH_SOCK at Bitwarden's SSH agent even when Bitwarden
+# wasn't running it, which broke ssh and ssh-add for everyone else. Swap that
+# line, where it was, for bitwarden.sh's, which only does so while it is.
+OLD='export SSH_AUTH_SOCK="$HOME/.bitwarden-ssh-agent.sock"'
+NEW='if [ -S "$HOME/.bitwarden-ssh-agent.sock" ]; then export SSH_AUTH_SOCK="$HOME/.bitwarden-ssh-agent.sock"; fi'
+
+[ -f ~/.bashrc ] || exit 0
+grep -qxF "$OLD" ~/.bashrc || exit 0
+
+tmp="$(mktemp ~/.bashrc.XXXXXX)" || exit 1
+awk -v old="$OLD" -v new="$NEW" '$0 == old { print new; next } { print }' ~/.bashrc > "$tmp" \
+  && cat "$tmp" > ~/.bashrc
+status=$?
+rm -f "$tmp"
+exit $status