Fix SPA 404 fallback: register ErrorPage /index.html for Vue Router

src/main/java/com/reportdist/config/WebConfig.java

@@ -1,12 +1,15 @@
 package com.reportdist.config;
 
+import org.springframework.boot.web.server.ErrorPage;
+import org.springframework.boot.web.server.ErrorPageRegistrar;
+import org.springframework.boot.web.server.ErrorPageRegistry;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.servlet.config.annotation.CorsRegistry;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 @Configuration
-public class WebConfig implements WebMvcConfigurer {
+public class WebConfig implements WebMvcConfigurer, ErrorPageRegistrar {
 
     @Override
     public void addCorsMappings(CorsRegistry registry) {
@@ -21,4 +24,9 @@ public class WebConfig implements WebMvcConfigurer {
         registry.addResourceHandler("/uploads/**")
                 .addResourceLocations("file:./uploads/");
     }
-}
+
+    @Override
+    public void registerErrorPages(ErrorPageRegistry registry) {
+        registry.addErrorPages(new ErrorPage("/index.html"));
+    }
+}