(converter) Add academia recognition to DomainProcessor

The code now includes an additional function in the DomainProcessor class that checks if a domain is associated with academia. An academic domain is identified by the ".edu" TLD, or fits a specific regex pattern matching domains like *.ac.ccTld or *.edu.ccTld.

 If these conditions are met, the search term "special:academia" is added to the domain.

 The existing academia search filter uses personalized pagerank to select academia-adjacent domains, but it isn't working very well.  The hope is that filtering on domain names will be more effective, and that it can supplant the ranking-based approach.

code/processes/converting-process/src/main/java/nu/marginalia/converting/processor/DomainProcessor.java

@@ -22,6 +22,7 @@ import org.slf4j.LoggerFactory;
 
 import java.sql.SQLException;
 import java.util.*;
+import java.util.regex.Pattern;
 
 public class DomainProcessor {
     private final DocumentProcessor documentProcessor;
@@ -94,6 +95,10 @@ public class DomainProcessor {
             terms.add(HtmlFeature.COOKIES.getKeyword());
         }
 
+        if (isAcademicDomain(ret.domain)) {
+            terms.add("special:academia");
+        }
+
         for (var document : ret.documents) {
             if (document.details == null)
                 continue;
@@ -114,6 +119,19 @@ public class DomainProcessor {
         return ret;
     }
 
+
+    private static final Pattern academicPattern = Pattern.compile(".*\\.(ac|edu)\\.[a-z]{2}$");
+    private boolean isAcademicDomain(EdgeDomain domain) {
+
+        if (domain.domain.endsWith(".edu"))
+            return true;
+
+        if (academicPattern.matcher(domain.domain).matches())
+            return true;
+
+        return false;
+    }
+
     private void fixBadCanonicalTag(CrawledDocument doc) {
         // Some sites have a canonical tag that points to a different domain,
         // but our loader can not support this, so we point these back to the