refactor(ui): avoid newlines in tr() strings

* Move newline characters out of translatable text passed to `tr()` to avoid
  translators accidentally altering formatting and to ensure correct argument
  substitution.
* Standardize string concatenation for the summary report and invalid key
  database details in the UI to improve translation safety and readability.
* Purely formatting/refactor changes; no functional behavior altered.

Author: saturneric

src/ui/main_window/MainWindow.cpp

@@ -314,8 +314,8 @@ auto MainWindow::check_and_notify_invalid_key_dbs() -> void {
   for (const auto& key_db : key_dbs) {
     if (!key_db.valid) {
       invalid_count++;
-      details +=
-          tr("Name: %1\nPath: %2\n\n").arg(key_db.name, key_db.origin_path);
+      details += tr("Name: %1").arg(key_db.name) + "\n" +
+                 tr("Path: %1").arg(key_db.origin_path) + "\n\n";
     }
   }
 

src/ui/main_window/MainWindowSlotFunction.cpp

@@ -340,19 +340,20 @@ void MainWindow::slot_result_analyse_show_helper(
 
   // Prepare summary section
   summary.append("# " + tr("Summary Report") + "\n\n");
-  summary.append("- " + tr("Total Operations: %1\n").arg(opera_results.size()));
-  summary.append("- " + tr("Successful: %1\n").arg(success_count));
-  summary.append("- " + tr("Warnings: %1\n").arg(warn_count));
-  summary.append("- " + tr("Failures: %1\n").arg(fail_count));
+  summary.append("- " + tr("Total Operations: %1").arg(opera_results.size()) +
+                 "\n");
+  summary.append("- " + tr("Successful: %1").arg(success_count) + "\n");
+  summary.append("- " + tr("Warnings: %1").arg(warn_count) + "\n");
+  summary.append("- " + tr("Failures: %1").arg(fail_count) + "\n");
 
   if (!failed_tags.isEmpty()) {
     summary.append("- " +
-                   tr("Failed Objects: %1\n").arg(failed_tags.join(", ")));
+                   tr("Failed Objects: %1").arg(failed_tags.join(", ") + "\n"));
   }
 
   if (!warning_tags.isEmpty()) {
-    summary.append("- " +
-                   tr("Warning Objects: %1\n").arg(warning_tags.join(", ")));
+    summary.append(
+        "- " + tr("Warning Objects: %1").arg(warning_tags.join(", ") + "\n"));
   }
 
   // Display the final report in the info board