Track gpg-agent passphrase caching config

Bumps the GPG passphrase cache from the 10-minute default to 8 hours
(24h hard cap) and switches to pinentry-qt for a native KDE dialog, so
signed commits stop re-prompting constantly.

zsh/.zshrc

@@ -112,6 +112,10 @@ command -v zoxide >/dev/null && eval "$(zoxide init zsh)"
 
 # User configuration
 
+# Needed for gpg-agent to prompt on the right terminal when pinentry falls
+# back to a tty (e.g. pinentry-curses); harmless no-op with pinentry-qt.
+export GPG_TTY=$(tty)
+
 # export MANPATH="/usr/local/man:$MANPATH"
 
 # You may need to manually set your language environment