feat(web): AvatarUpload component

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

web/src/components/AvatarUpload.vue

@@ -0,0 +1,99 @@
+<template>
+  <div class="avatar-upload">
+    <div class="preview" :class="{ empty: !previewUrl }">
+      <img v-if="previewUrl" :src="previewUrl" alt="avatar" />
+      <Icon v-else icon="mdi:account-circle-outline" />
+    </div>
+    <div class="actions">
+      <input
+        ref="fileInput"
+        type="file"
+        accept="image/png,image/jpeg,image/webp"
+        class="hidden"
+        @change="onFile"
+      />
+      <button type="button" class="btn-sm" @click="fileInput?.click()">
+        {{ previewUrl ? '更换' : '上传' }}
+      </button>
+      <button v-if="previewUrl" type="button" class="btn-sm btn-danger" @click="clear">
+        删除
+      </button>
+    </div>
+    <p v-if="error" class="hint error">{{ error }}</p>
+    <p v-else class="hint">PNG / JPG / WebP，≤200 KB</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, watch } from 'vue';
+import { Icon } from '@iconify/vue';
+
+const props = defineProps<{ modelValue: string | null }>();
+const emit = defineEmits<{ 'update:modelValue': [value: string | null] }>();
+
+const previewUrl = ref<string | null>(props.modelValue);
+const error = ref<string | null>(null);
+const fileInput = ref<HTMLInputElement | null>(null);
+
+watch(() => props.modelValue, (v) => { previewUrl.value = v; });
+
+function onFile(ev: Event) {
+  const file = (ev.target as HTMLInputElement).files?.[0];
+  if (!file) return;
+  if (!['image/png', 'image/jpeg', 'image/webp'].includes(file.type)) {
+    error.value = '仅支持 PNG / JPG / WebP';
+    return;
+  }
+  if (file.size > 200 * 1024) {
+    error.value = `图片 ${(file.size / 1024).toFixed(0)} KB 超过 200 KB 上限`;
+    return;
+  }
+  error.value = null;
+  const reader = new FileReader();
+  reader.onload = () => {
+    const dataUrl = reader.result as string;
+    previewUrl.value = dataUrl;
+    emit('update:modelValue', dataUrl);
+  };
+  reader.readAsDataURL(file);
+}
+
+function clear() {
+  previewUrl.value = null;
+  emit('update:modelValue', null);
+  if (fileInput.value) fileInput.value.value = '';
+}
+</script>
+
+<style lang="scss" scoped>
+.avatar-upload { display: flex; flex-direction: column; gap: 8px; align-items: flex-start; }
+
+.preview {
+  width: 80px; height: 80px; border-radius: 50%;
+  background: var(--bg-card); display: flex; align-items: center; justify-content: center;
+  overflow: hidden;
+
+  img { width: 100%; height: 100%; object-fit: cover; }
+  &.empty :deep(svg) { font-size: 48px; opacity: 0.4; }
+}
+
+.actions { display: flex; gap: 8px; }
+.hidden { display: none; }
+
+.btn-sm {
+  padding: 6px 14px;
+  background: var(--hover-bg);
+  border-radius: var(--radius-sm);
+  font-size: 12px;
+  font-weight: 600;
+  transition: all var(--transition-fast);
+  &:hover { background: var(--color-primary); color: white; }
+}
+
+.btn-danger {
+  &:hover { background: #f44336; color: white; }
+}
+
+.hint { font-size: 12px; opacity: 0.6; margin: 0; }
+.hint.error { color: #f44336; opacity: 1; }
+</style>