docs: scope the foreign-script and surefire claims to what the code does

hasForeignScript detects by alphabet, so Latin-script leakage such as
the observed French "contiennent" is not caught. Say so in the javadoc
and admit the gap in the design doc rather than implying coverage.

failIfNoTests catches a misplaced or misnamed test class, not a
disabled one: an @Disabled class still reports as skipped and the
build stays green.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F3jSvSTrG4qsniLSr6TpC6

pom.xml

@@ -71,8 +71,9 @@
         <configuration>
           <!-- The pin above guards against a surefire version that quietly stops
                discovering tests. It does not guard against a test class being
-               misplaced, misnamed or disabled, which ends the same way: a green
-               build that ran nothing. Failing on an empty suite closes that gap. -->
+               misplaced or misnamed, which ends the same way: a green build that
+               ran nothing. Failing on an empty suite closes that gap. A disabled
+               class is still reported as skipped, so it is not covered here. -->
           <failIfNoTests>true</failIfNoTests>
         </configuration>
       </plugin>