Rebase opt-in fingerprint workaround onto KScreenLocker 6.7.5

plasma-fingerprint-workaround/README.md

@@ -21,7 +21,7 @@ restores the current KScreenLocker package from Fedora's `fedora` or `updates`
 repository.
 
 The provided build currently supports Fedora 44 on x86_64 and is based on
-`kscreenlocker-6.7.4-1.fc44`. A different base version is rejected by default.
+`kscreenlocker-6.7.5-1.fc44`. A different base version is rejected by default.
 To intentionally install the older provided build after a KScreenLocker update:
 
 ```bash
@@ -41,7 +41,7 @@ Install the resulting package directly through the controller:
 
 ```bash
 sudo plasma-fingerprint-workaround enable \
-  --rpm rpmbuild/RPMS/x86_64/kscreenlocker-6.7.4-1.fc44.ajp5.x86_64.rpm
+  --rpm rpmbuild/RPMS/x86_64/kscreenlocker-6.7.5-1.fc44.ajp6.x86_64.rpm
 ```
 
 For another upstream version, supply its version, Fedora base release, and
@@ -58,3 +58,21 @@ A locally built package based on a different installed version requires
 `--force`. This flag permits the version mismatch and allows DNF to downgrade;
 it does not bypass the package identity, architecture, integrity, or workaround
 metadata checks.
+
+## Authentication regression tests
+
+With an extracted source tree and the patches applied in numeric order:
+
+```bash
+cmake -S plasma-fingerprint-workaround/tests/authentication \
+  -B local/fingerprint-tests -DKSCREENLOCKER_SOURCE=/path/to/patched/kscreenlocker
+cmake --build local/fingerprint-tests
+ctest --test-dir local/fingerprint-tests --output-on-failure
+```
+
+These tests compile the upstream authentication classes against a simulated
+PAM backend. They check retries after fingerprint timeout or temporary
+unavailability, preservation of the password conversation, absent smartcards,
+missing modules, the grace-period guard and incorrect passwords. They never
+access the system's authentication configuration. Actual reader behaviour and
+the lock-screen interface still require testing on the laptop.