重构项目结构，移除旧Java客户端，添加前后端目录

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/DiffModal.vue

@@ -0,0 +1,54 @@
+<script setup>
+import { ref, watch } from 'vue'
+import { useProjectsStore } from '../stores/projects'
+import { useModalsStore } from '../stores/modals'
+import { svnApi } from '../api/client'
+
+const store = useProjectsStore()
+const modals = useModalsStore()
+const diffText = ref('')
+const loading = ref(false)
+
+watch(() => modals.diffOpen, async (open) => {
+  const id = store.currentId?.value ?? store.currentId
+  if (open && id) {
+    loading.value = true
+    diffText.value = ''
+    try {
+      const res = await svnApi.diff(id, modals.diffPath || undefined)
+      diffText.value = res.data?.diff ?? res.data ?? ''
+    } catch (e) {
+      diffText.value = '获取差异失败: ' + (e.response?.data || e.message)
+    } finally {
+      loading.value = false
+    }
+  }
+})
+</script>
+
+<template>
+  <div v-if="modals.diffOpen" class="modal-overlay" @click.self="modals.closeDiff()">
+    <div class="modal modal-lg">
+      <div class="modal-header">
+        <h3>差异</h3>
+        <button class="modal-close" @click="modals.closeDiff()">&times;</button>
+      </div>
+      <div class="modal-body">
+        <div v-if="loading" class="loading">加载中...</div>
+        <pre v-else class="diff-content">{{ diffText || '(无差异)' }}</pre>
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; z-index: 1000; }
+.modal { background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 8px; min-width: 400px; max-height: 80vh; display: flex; flex-direction: column; }
+.modal-lg { width: 90vw; max-width: 800px; }
+.modal-header { display: flex; justify-content: space-between; align-items: center; padding: 1rem; border-bottom: 1px solid var(--border-color); }
+.modal-header h3 { margin: 0; font-size: 1rem; }
+.modal-close { background: none; border: none; color: var(--text-secondary); font-size: 1.5rem; cursor: pointer; }
+.modal-body { padding: 1rem; overflow: auto; }
+.loading { color: var(--text-secondary); }
+.diff-content { font-family: var(--font-mono), monospace; font-size: 12px; white-space: pre; margin: 0; color: var(--text-primary); }
+</style>