T-1: initialize monorepo structure with backend and frontend scaffolds

Backend: Spring Boot 3.5.11 on Java 25, Maven with wrapper, hexagonal
architecture package layout (domain/application/adapter/config), health
endpoint with integration test. Originally planned for Spring Boot 4.0
but pivoted due to massive package reorganization in 4.0 (see addenda
in research and plan docs).

Frontend: Vue 3 scaffolded via create-vue with TypeScript, Vue Router,
Vitest, ESLint, Prettier. Pivoted from Svelte due to ecosystem maturity
concerns (broken router ecosystem for Svelte 5).

Also: extended .gitignore for Java/Maven and Node/Vue artifacts, updated
CLAUDE.md with tech stack, build commands, agent documentation sections,
and document integrity rule.

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

backend/src/main/java/de/fete/FeteApplication.java

@@ -0,0 +1,12 @@
+package de.fete;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class FeteApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(FeteApplication.class, args);
+    }
+}

backend/src/main/java/de/fete/adapter/in/web/HealthController.java

@@ -0,0 +1,15 @@
+package de.fete.adapter.in.web;
+
+import java.util.Map;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HealthController {
+
+    @GetMapping("/health")
+    public Map<String, String> health() {
+        return Map.of("status", "ok");
+    }
+}

backend/src/main/java/de/fete/adapter/in/web/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Inbound web adapter: REST controllers, DTOs, and request/response mappers.
+ *
+ * <p>May depend on application and domain layers.
+ */
+package de.fete.adapter.in.web;

backend/src/main/java/de/fete/adapter/out/persistence/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Outbound persistence adapter: JPA entities, Spring Data repositories, and mappers.
+ *
+ * <p>May depend on application and domain layers.
+ */
+package de.fete.adapter.out.persistence;

backend/src/main/java/de/fete/application/service/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Application services: use case implementations.
+ *
+ * <p>May depend on domain only. Uses {@code @Service} for component scanning.
+ */
+package de.fete.application.service;

backend/src/main/java/de/fete/config/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Configuration: Spring {@code @Configuration} and {@code @Bean} definitions.
+ *
+ * <p>Wiring layer — may depend on all other packages.
+ */
+package de.fete.config;

backend/src/main/java/de/fete/domain/model/package-info.java

@@ -0,0 +1,7 @@
+/**
+ * Domain model: entities and value objects.
+ *
+ * <p>Plain Java — no framework annotations allowed.
+ * This package has no dependencies on other packages.
+ */
+package de.fete.domain.model;

backend/src/main/java/de/fete/domain/port/in/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Driving ports: use case interfaces that the application layer implements.
+ *
+ * <p>Plain Java interfaces — no framework annotations allowed.
+ */
+package de.fete.domain.port.in;

backend/src/main/java/de/fete/domain/port/out/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * Driven ports: repository and external service interfaces.
+ *
+ * <p>Plain Java interfaces — no framework annotations allowed.
+ */
+package de.fete.domain.port.out;

backend/src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.application.name=fete