fix: Address SonarCloud findings (catch Exception, drop unused import)

Author: thced

src/main/java/com/retailsvc/http/internal/RequestPreparationFilter.java

@@ -143,14 +143,14 @@ private void fireAfterHooks(HttpExchange exchange, Request request) {
     for (AfterResponseHook hook : afterHooks) {
       try {
         hook.after(request, response);
-      } catch (Throwable t) {
+      } catch (Exception t) {
         LOG.debug("after-response hook threw", t);
       }
     }
     for (Runnable runnable : snapshot) {
       try {
         runnable.run();
-      } catch (Throwable t) {
+      } catch (Exception t) {
         LOG.debug("after-response runnable threw", t);
       }
     }

src/test/java/com/retailsvc/http/internal/RequestPreparationFilterTest.java

@@ -27,7 +27,6 @@
 import com.sun.net.httpserver.Headers;
 import com.sun.net.httpserver.HttpExchange;
 import java.io.ByteArrayInputStream;
-import java.io.IOException;
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.util.List;