refactor!: move the S3 storage backend to the fess-storage-s3 plugin

pom.xml

@@ -1278,17 +1278,6 @@
 			<artifactId>oauth2-oidc-sdk</artifactId>
 			<version>${oauth2.oidc.sdk.version}</version>
 		</dependency>
-		<dependency>
-			<groupId>software.amazon.awssdk</groupId>
-			<artifactId>s3</artifactId>
-			<version>${s3.version}</version>
-			<exclusions>
-				<exclusion>
-					<groupId>software.amazon.awssdk</groupId>
-					<artifactId>netty-nio-client</artifactId>
-				</exclusion>
-			</exclusions>
-		</dependency>
 		<dependency>
 			<groupId>org.apache.httpcomponents.client5</groupId>
 			<artifactId>httpclient5</artifactId>
@@ -1478,6 +1467,19 @@
 					<groupId>com.google.cloud</groupId>
 					<artifactId>google-cloud-storage</artifactId>
 				</exclusion>
+				<exclusion>
+					<!-- The AWS SDK for S3 is 30 jars and 8.4 MiB of the distribution for a
+					     protocol that most installations never crawl, and it moves faster than
+					     Fess does. It ships in the fess-storage-s3 plugin instead, which carries
+					     the SDK and registers S3Client with crawlerClientCreator. fess-crawler
+					     still compiles S3Client against the SDK, so this exclusion is what keeps
+					     the jars out of the war; the classes stay in fess-crawler.jar and cost a
+					     few tens of KiB.
+					     Do not relocate the SDK packages in that plugin: S3Client lives outside
+					     its jar and resolves them by their original names. -->
+					<groupId>software.amazon.awssdk</groupId>
+					<artifactId>s3</artifactId>
+				</exclusion>
 			</exclusions>
 		</dependency>
 		<dependency>

src/main/java/org/codelibs/fess/mylasta/direction/FessConfig.java

@@ -443,7 +443,7 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
     /** The key of the configuration. e.g. http,https */
     String CRAWLER_WEB_PROTOCOLS = "crawler.web.protocols";
 
-    /** The key of the configuration. e.g. file,smb,smb1,ftp,s3 */
+    /** The key of the configuration. e.g. file,smb,smb1,ftp */
     String CRAWLER_FILE_PROTOCOLS = "crawler.file.protocols";
 
     /** The key of the configuration. e.g. ^FESS_ENV_.* */
@@ -3571,7 +3571,7 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
 
     /**
      * Get the value for the key 'crawler.file.protocols'. <br>
-     * The value is, e.g. file,smb,smb1,ftp,s3 <br>
+     * The value is, e.g. file,smb,smb1,ftp <br>
      * comment: Supported file protocols for crawling.
      * @return The value of found property. (NotNull: if not found, exception but basically no way)
      */
@@ -14560,7 +14560,7 @@ protected java.util.Map<String, String> prepareGeneratedDefaultMap() {
             defaultMap.put(FessConfig.CRAWLER_DOCUMENT_FULLSTOP_CHARS, "u002eu06d4u2e3cu3002");
             defaultMap.put(FessConfig.CRAWLER_CRAWLING_DATA_ENCODING, "UTF-8");
             defaultMap.put(FessConfig.CRAWLER_WEB_PROTOCOLS, "http,https");
-            defaultMap.put(FessConfig.CRAWLER_FILE_PROTOCOLS, "file,smb,smb1,ftp,s3");
+            defaultMap.put(FessConfig.CRAWLER_FILE_PROTOCOLS, "file,smb,smb1,ftp");
             defaultMap.put(FessConfig.CRAWLER_DATA_ENV_PARAM_KEY_PATTERN, "^FESS_ENV_.*");
             defaultMap.put(FessConfig.CRAWLER_IGNORE_ROBOTS_TXT, "false");
             defaultMap.put(FessConfig.CRAWLER_IGNORE_ROBOTS_TAGS, "false");

src/main/java/org/codelibs/fess/storage/StorageClientFactory.java

@@ -72,8 +72,10 @@ public static StorageType detectStorageType(final String endpoint) {
     public static StorageClient createClient(final FessConfig fessConfig) {
         final String componentName = componentName(fessConfig.getStorageType(), fessConfig.getStorageEndpoint());
         if (!ComponentUtil.hasComponent(componentName)) {
-            throw new StorageException("No storage client is registered as " + componentName + " for storage.type="
-                    + fessConfig.getStorageType() + ". Install the plugin that provides it, such as fess-storage-gcs for gcs.");
+            throw new StorageException(
+                    "No storage client is registered as " + componentName + " for storage.type=" + fessConfig.getStorageType()
+                            + ". Every backend ships as a fess-storage-* plugin: install fess-storage-s3 for s3 and s3_compat, "
+                            + "or fess-storage-gcs for gcs.");
         }
         if (logger.isDebugEnabled()) {
             logger.debug("Creating {} for endpoint: {}", componentName, fessConfig.getStorageEndpoint());
@@ -87,10 +89,10 @@ public static StorageClient createClient(final FessConfig fessConfig) {
      * Returns the name of the DI component that serves a storage type.
      *
      * <p>The mapping from a {@code storage.type} value to an implementation lives in the DI
-     * definition rather than here, which is what lets the clients ship as plugins: core no longer
-     * names GcsStorageClient or S3StorageClient, and a plugin registering
-     * {@code <type>StorageClient} is reachable by setting {@code storage.type=<type>}. The
-     * components are prototypes because every caller closes the client it was handed.</p>
+     * definition rather than here, which is what lets the clients ship as plugins: core names no
+     * implementation at all, and a plugin registering {@code <type>StorageClient} is reachable by
+     * setting {@code storage.type=<type>}. The components are prototypes because every caller
+     * closes the client it was handed.</p>
      *
      * @param typeStr the configured type, blank or {@code auto} to detect from the endpoint
      * @param endpoint the storage endpoint, used only when detecting