feat(admin): 来源归因展示——渠道徽章/筛选/来源识别卡/渠道构成图

- 类型：VisitorRow 补 channel/platform/variant/search_term/resolution，新增
  AttributionInfo/AttributionBlock，详情响应带 attribution 块；dashboard
  响应补 channels（ChannelItem）
- 工具：CHANNEL_LABELS 八渠道元数据 + channelBadge 徽章串（搜索词/标签/
  冲突后缀，未归因回 —）
- 访客列表：首触来源列升级渠道徽章（first_source 进 tooltip 兜底），
  筛选栏加渠道下拉（channel= 枚举）
- 访客详情：首触来源升级来源识别卡（渠道徽章/平台/国家站/搜索词显著
  展示，label_only/conflict 诚实标注，冲突并列两路证据文本渲染），
  无归因旧数据降级原 first_source 口径
- 总览：来源饼图改渠道构成（标签/颜色按渠道绑定 CHANNEL_LABELS），
  下方保留平台明细小表（原 sources 域名口径）

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

admin/src/views/tracker/visitor/detail.vue

@@ -57,8 +57,56 @@
                 }}
               </span>
             </ElDescriptionsItem>
-            <ElDescriptionsItem label="首触来源">
-              <div class="flex-c flex-wrap gap-1.5">
+            <ElDescriptionsItem label="首触来源" :span="2">
+              <!-- 来源识别卡：归因引擎结论（渠道徽章/平台/国家站/搜索词/可信度标注） -->
+              <div v-if="firstTouch" class="source-card">
+                <div class="flex-c flex-wrap gap-x-2 gap-y-1.5">
+                  <span
+                    class="channel-tag"
+                    :style="{
+                      color: firstTouchMeta.color,
+                      background: firstTouchMeta.color + '1A',
+                      borderColor: firstTouchMeta.color + '59'
+                    }"
+                  >
+                    {{ firstTouchMeta.icon }} {{ firstTouchMeta.label }}
+                  </span>
+                  <span v-if="firstTouch.platform" class="font-medium whitespace-nowrap">
+                    {{ firstTouch.platform }}
+                  </span>
+                  <span v-if="firstTouch.variant" class="text-xs text-g-500 whitespace-nowrap">
+                    {{ firstTouch.variant }}
+                  </span>
+                  <span
+                    v-if="firstTouch.resolution === 'label_only'"
+                    class="text-xs text-g-500 whitespace-nowrap"
+                  >
+                    仅UTM标签
+                  </span>
+                  <span
+                    v-else-if="firstTouch.resolution === 'conflict'"
+                    class="text-xs source-conflict whitespace-nowrap"
+                  >
+                    证据冲突
+                  </span>
+                </div>
+                <div v-if="firstTouch.search_term" class="search-term-row">
+                  <span class="shrink-0 text-xs text-g-600">搜索词</span>
+                  <span class="search-term">{{ firstTouch.search_term }}</span>
+                </div>
+                <!-- 冲突时并列展示两路证据（文本插值渲染，禁 v-html） -->
+                <div
+                  v-if="firstTouch.resolution === 'conflict' && conflictEvidences.length"
+                  class="conflict-box"
+                >
+                  <div v-for="(ev, i) in conflictEvidences" :key="i" class="conflict-line">
+                    <span class="shrink-0 text-xs text-g-600">{{ ev.label }}</span>
+                    <span class="text-xs">{{ ev.text }}</span>
+                  </div>
+                </div>
+              </div>
+              <!-- 降级：无归因（旧数据未重算）→ 原 first_source 口径 + UTM 标签 -->
+              <div v-else class="flex-c flex-wrap gap-1.5">
                 <span class="whitespace-nowrap">{{ firstSourceText }}</span>
                 <ElTag
                   v-for="(val, key) in detail.first_utm"
@@ -368,6 +416,7 @@
     getSession,
     getTimeline,
     getVisitor,
+    type AttributionInfo,
     type RawBatchRow,
     type SessionSummary,
     type TimelineEvent,
@@ -375,7 +424,7 @@
     type TimelineSession,
     type VisitorDetail
   } from '@/api/tracker/visitors'
-  import { countryFlag, formatDateTime, formatStay } from '@/utils/tracker'
+  import { CHANNEL_LABELS, countryFlag, formatDateTime, formatStay } from '@/utils/tracker'
   import EventTimeline from './components/EventTimeline.vue'
 
   defineOptions({ name: 'TrackerVisitorDetail' })
@@ -435,6 +484,48 @@
     return d.first_referrer_domain || d.first_utm?.utm_source || '直接访问'
   })
 
+  // ---------- 来源识别卡（归因引擎结论；旧数据未重算时降级上面的 first_source 口径） ----------
+  /** detail 字段类型收窄：归因 detail 是后端拼的 dict，只接受纯对象 */
+  const isRecord = (v: unknown): v is Record<string, unknown> =>
+    typeof v === 'object' && v !== null && !Array.isArray(v)
+
+  /** 证据记录 → 一行可读文本：渠道 · 平台（· 变体）+ referrer 域名括注 */
+  const formatEvidence = (e: Record<string, unknown>, withHost: boolean): string => {
+    const segs = [
+      CHANNEL_LABELS[String(e.channel ?? '')]?.label || String(e.channel ?? ''),
+      String(e.platform ?? ''),
+      String(e.variant ?? '')
+    ]
+      .filter(Boolean)
+      .join(' · ')
+    const host = withHost && e.referrer_host ? `（${String(e.referrer_host)}）` : ''
+    return `${segs}${host}`
+  }
+
+  /** 首触归因（attribution.first_touch；无分类行时后端给 null → 模板走降级分支） */
+  const firstTouch = computed<AttributionInfo | null>(
+    () => detail.value?.attribution?.first_touch ?? null
+  )
+
+  /** 渠道徽章元数据（未知渠道值兜底 unknown 项） */
+  const firstTouchMeta = computed(
+    () => CHANNEL_LABELS[firstTouch.value?.channel ?? ''] ?? CHANNEL_LABELS.unknown
+  )
+
+  /** conflict 时并列的两路证据（referrer 观察 vs UTM 标签），文本插值渲染 */
+  const conflictEvidences = computed(() => {
+    const d = firstTouch.value?.detail
+    if (!isRecord(d)) return []
+    const out: { label: string; text: string }[] = []
+    if (isRecord(d.referrer_evidence)) {
+      out.push({ label: '观察证据', text: formatEvidence(d.referrer_evidence, true) })
+    }
+    if (isRecord(d.utm_evidence)) {
+      out.push({ label: '标签证据', text: formatEvidence(d.utm_evidence, false) })
+    }
+    return out
+  })
+
   /** 统计数字 4 项（?? 只兜 nullish，0 正常显示） */
   const statTiles = computed(() => [
     { label: '访问次数', value: detail.value ? String(detail.value.visit_count) : '—' },
@@ -649,6 +740,55 @@
     font-family: var(--el-font-family-mono, monospace);
   }
 
+  // 来源识别卡（首触归因结论）
+  .source-card {
+    display: flex;
+    flex-direction: column;
+    gap: 6px;
+    min-width: 0;
+  }
+
+  .channel-tag {
+    padding: 2px 8px;
+    font-size: 12px;
+    line-height: 18px;
+    border: 1px solid transparent;
+    border-radius: 4px;
+    white-space: nowrap;
+  }
+
+  .search-term-row {
+    display: flex;
+    gap: 6px;
+    align-items: baseline;
+  }
+
+  .search-term {
+    font-size: 14px;
+    font-weight: 600;
+    color: var(--el-color-primary);
+    word-break: break-all;
+  }
+
+  .source-conflict {
+    color: var(--el-color-danger);
+  }
+
+  .conflict-box {
+    display: flex;
+    flex-direction: column;
+    gap: 4px;
+    padding: 8px 10px;
+    border-radius: 6px;
+    background: var(--el-fill-color-lighter);
+
+    .conflict-line {
+      display: flex;
+      gap: 8px;
+      align-items: baseline;
+    }
+  }
+
   .stat-tile {
     display: flex;
     flex-direction: column;