Fix fprintd AlreadyInUse error by respecting done flag

VerifyStart was called unconditionally on retry/no-match statuses,
ignoring the done parameter from fprintd's VerifyStatus signal.
When done=False the verify session is still active, causing
AlreadyInUse errors. Now only restarts verification when done=True.

src/moonlock/fingerprint.py

@@ -143,13 +143,15 @@ class FingerprintListener:
             return
 
         if status in _RETRY_STATUSES:
-            # Retry silently — finger wasn't read properly
-            self._device_proxy.VerifyStart("(s)", "any")
+            # Retry — finger wasn't read properly
+            if done:
+                self._device_proxy.VerifyStart("(s)", "any")
             return
 
         if status == "verify-no-match":
             if self._on_failure:
                 self._on_failure()
             # Restart verification for another attempt
-            self._device_proxy.VerifyStart("(s)", "any")
+            if done:
+                self._device_proxy.VerifyStart("(s)", "any")
             return