Broaden the test-suite header comment

The comment still described only the original scalar/S-8 scope; the suite also carries the SA-* signing/encryption regressions and the new Locksmith wire-compat and restart-survival cases.

tests/meson.build

@@ -1,5 +1,7 @@
 # Statum test suite: scalar/list serialization round-trips (public + encrypted
-# paths) and the cross-namespace typed-action private-data reproduction (S-8).
+# paths), the cross-namespace typed-action private-data reproduction (S-8),
+# the signing/encryption regression cases (SA-*), and the Locksmith
+# wire-compat + restart-survival cases for the crypto providers.
 # Prints PASS/FAIL lines and exits non-zero on failure.
 
 statum_tests = executable('statum-tests',