feat: add client-side email viewer for .msg and .eml files

Renders Outlook MSG and RFC 822 EML files entirely in the browser
without server-side conversion.

- MSG files decoded with @kenjiuno/msgreader (bundled to browser IIFE
  via frontend-maven-plugin + esbuild); patches PT_STRING8 into
  TYPE_MAPPING to fix v1.11.0 field-decoding bug
- EML files parsed with eml-parse-js (UMD bundle from WebJar); wraps
  readEml to suppress harmless InvalidCharacterError console noise from
  the library's base64 auto-detection heuristic
- HTML bodies sanitised with DOMPurify (XSS protection); data: URIs
  allowed on <img> so CID-resolved inline images survive sanitisation
- Inline CID images resolved to data URIs before sanitisation
- Attachments downloadable via Blob object-URLs (MSG uses
  reader.getAttachment(); EML uses att.data64 base64 content)
- Uses $wnd.XMLHttpRequest throughout to keep ArrayBuffer in host-page
  realm, avoiding cross-frame instanceof failures in the MSGReader bundle
- Viewer registered for PRONOM fmt/950 (EML), fmt/952 (MSG),
  message/rfc822, application/vnd.ms-outlook, and .eml/.msg extensions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: luis100

roda-ui/roda-wui/pom.xml

@@ -610,6 +610,33 @@
             <artifactId>filesaver.js</artifactId>
             <version>2.0.4</version>
         </dependency>
+        <!-- Email viewer -->
+        <!-- Note: jars below may take a few hours to propagate to Maven Central after deployment -->
+        <dependency>
+            <!-- Outlook .msg reader — CommonJS only; bundled to browser IIFE by frontend-maven-plugin -->
+            <groupId>org.webjars.npm</groupId>
+            <artifactId>github-com-HiraokaHyperTools-msgreader</artifactId>
+            <version>1.11.0</version>
+        </dependency>
+        <dependency>
+            <!-- RFC 822 .eml parser — browser UMD bundle served directly from webjars path -->
+            <groupId>org.webjars.npm</groupId>
+            <artifactId>github-com-MQpeng-eml-parse-js</artifactId>
+            <version>1.1.15</version>
+        </dependency>
+        <dependency>
+            <!-- Base64 codec — required by eml-parse-js UMD bundle as window.Base64 -->
+            <groupId>org.webjars.npm</groupId>
+            <artifactId>js-base64</artifactId>
+            <version>3.7.7</version>
+        </dependency>
+        <dependency>
+            <!-- HTML sanitizer — prevents XSS from email body content -->
+            <groupId>org.webjars.npm</groupId>
+            <artifactId>dompurify</artifactId>
+            <version>3.2.6</version>
+        </dependency>
+        <!-- / Email viewer -->
         <!-- Spring boot -->
         <dependency>
             <groupId>org.springframework.boot</groupId>
@@ -675,6 +702,71 @@
                     <encoding>UTF-8</encoding>
                 </configuration>
             </plugin>
+            <!--
+              Bundles @kenjiuno/msgreader (CommonJS, no browser build) into a
+              browser-compatible IIFE using esbuild.  All transitive npm deps
+              (iconv-lite, @kenjiuno/decompressrtf) are inlined by esbuild's
+              bundler.  The output lands in target/classes/static/js/msgreader/
+              and is served by Spring Boot at /js/msgreader/MsgReader.js.
+            -->
+            <plugin>
+                <groupId>com.github.eirslett</groupId>
+                <artifactId>frontend-maven-plugin</artifactId>
+                <version>1.15.1</version>
+                <configuration>
+                    <workingDirectory>${project.basedir}/src/main/js</workingDirectory>
+                    <!-- Keep Node.js binary out of src/ -->
+                    <installDirectory>${project.build.directory}/frontend</installDirectory>
+                    <nodeVersion>v22.14.0</nodeVersion>
+                </configuration>
+                <executions>
+                    <execution>
+                        <id>install-node-and-npm</id>
+                        <goals>
+                            <goal>install-node-and-npm</goal>
+                        </goals>
+                        <phase>generate-resources</phase>
+                    </execution>
+                    <execution>
+                        <id>npm-install</id>
+                        <goals>
+                            <goal>npm</goal>
+                        </goals>
+                        <phase>generate-resources</phase>
+                        <!-- default goal is 'install' -->
+                    </execution>
+                    <execution>
+                        <id>bundle-msgreader-for-browser</id>
+                        <goals>
+                            <goal>npx</goal>
+                        </goals>
+                        <phase>generate-resources</phase>
+                        <configuration>
+                            <arguments>esbuild entry.js
+                                --bundle
+                                --global-name=MSGReader
+                                --format=iife
+                                --platform=browser
+                                --outfile=${project.build.outputDirectory}/static/js/msgreader/MsgReader.js</arguments>
+                        </configuration>
+                    </execution>
+                    <execution>
+                        <id>bundle-emlparser-for-browser</id>
+                        <goals>
+                            <goal>npx</goal>
+                        </goals>
+                        <phase>generate-resources</phase>
+                        <configuration>
+                            <arguments>esbuild entry-eml.js
+                                --bundle
+                                --global-name=EmlParseJs
+                                --format=iife
+                                --platform=browser
+                                --outfile=${project.build.outputDirectory}/static/js/emlparser/EmlParseJs.js</arguments>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 </project>

roda-ui/roda-wui/src/main/java/org/roda/wui/client/browse/BitstreamPreview.java

@@ -58,6 +58,8 @@ public class BitstreamPreview<T extends IsIndexed> extends Composite {
   private static final String VIEWER_TYPE_HTML = "html";
   private static final String VIEWER_TYPE_PDF = "pdf";
   private static final String VIEWER_TYPE_IMAGE = "image";
+  private static final String VIEWER_TYPE_TIFF = "tiff";
+  private static final String VIEWER_TYPE_EMAIL = "email";
 
   private static final ClientMessages messages = GWT.create(ClientMessages.class);
 
@@ -189,6 +191,8 @@ private void preview() {
         audioPreview();
       } else if (type.equals(VIEWER_TYPE_VIDEO)) {
         videoPreview();
+      } else if (type.equals(VIEWER_TYPE_EMAIL)) {
+        emailPreview();
       } else {
         notSupportedPreview();
       }
@@ -251,6 +255,17 @@ public void onAttachOrDetach(AttachEvent event) {
 
   }
 
+  private void tiffPreview() {
+    TiffViewer tiffViewer = new TiffViewer(bitstreamDownloadUri);
+    panel.add(tiffViewer);
+  }
+
+  private void emailPreview() {
+    EmailViewer emailViewer = new EmailViewer(bitstreamDownloadUri, format, filename, onPreviewFailure);
+    panel.add(emailViewer);
+  }
+
+
   private void pdfPreview() {
 
     String viewerPdf = GWT.getHostPageBaseURL() + "webjars/pdf-js/web/viewer.html" + "?file="