Ship postlogin too, the other half of the seam kscreenlocker expects

fingerprint-auth alone was not enough. /etc/pam.d/kde-fingerprint is written
for a Fedora/authselect layout and its auth stack is two lines: a substack of
fingerprint-auth followed by an include of postlogin. Alpine ships neither.

With only the first supplied, the fingerprint MATCHED and PAM still answered
Permission denied -- the include of a missing service failing after the match
had already succeeded, which is a confusing way to be told a file is absent.
The daemon's own log said MATCH while pamtester said no.

On Fedora postlogin does lastlog and umask bookkeeping. Nothing here needs
that; what is needed is that the seam exists and contributes nothing, so the
stack's result stays the one the fingerprint substack produced. Hence four
optional pam_permit lines and a comment explaining why it is deliberately
empty rather than merely unfinished.

Also observed while testing, and worth knowing before anyone calls this
broken: the lock screen arms fingerprint ONCE when it appears, waits 30
seconds -- pam_fprintd's own timeout -- and then cancels and falls back to a
password. Pressing outside that window reaches nothing at all, and the daemon
records it as `verify: cancelled over 0 press(es)`.

packaging/APKBUILD

@@ -10,7 +10,7 @@
 # Alpine, so an APKBUILD that compiled from source could not be built by
 # anyone but us either.
 pkgname=fingerprintd
-pkgver=0.2.1
+pkgver=0.2.2
 pkgrel=0
 pkgdesc="Fingerprint daemon for the Fairphone 6 (FocalTech FT9391 behind QTEE)"
 url="https://forgejo.catcrafts.net/Catcrafts/fingerprintd"
@@ -106,6 +106,8 @@ package() {
 	# Vendor directory, so /etc/pam.d still overrides it.
 	install -Dm644 fingerprint-auth.pam \
 		"$pkgdir"/usr/lib/pam.d/fingerprint-auth
+	install -Dm644 postlogin.pam \
+		"$pkgdir"/usr/lib/pam.d/postlogin
 
 	# Documentation, not configuration: shipping an /etc/fingerprintd/
 	# actions.conf would be shipping a root shell nobody asked for. The