feat: 风险关键词红色标记 + 点击显示权重贡献

- 后端: _extract_reason_tokens 返回 [{token, weight}] 格式
- 前端: detect/batch 页面风险关键词使用红色标签样式
- 点击关键词弹窗显示权重值及判定倾向

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/app/ml/naive_bayes_classifier.py

@@ -119,7 +119,7 @@ class NaiveBayesSpamClassifier:
             "trained_at": self.metadata.get("trained_at"),
         }
 
-    def _extract_reason_tokens(self, text: str, classes: list[str], x_row) -> list[str]:
+    def _extract_reason_tokens(self, text: str, classes: list[str], x_row) -> list[dict]:
         try:
             vocab = self.vectorizer.vocabulary_
             feature_names = self.vectorizer.get_feature_names_out()
@@ -138,12 +138,12 @@ class NaiveBayesSpamClassifier:
                 if idx is None:
                     continue
                 delta = class_log_prob[spam_idx][idx] - class_log_prob[ham_idx][idx]
-                scored.append((token, delta))
+                scored.append({"token": token, "weight": round(delta, 4)})
 
-            scored.sort(key=lambda row: abs(row[1]), reverse=True)
-            return [token for token, _ in scored[:5]]
+            scored.sort(key=lambda row: abs(row["weight"]), reverse=True)
+            return scored[:5]
         except Exception:
-            return list(text[:5])
+            return [{"token": ch, "weight": 0.0} for ch in list(text[:5])]
 
     def model_info(self) -> dict:
         return {

miniprogram/app.wxss

@@ -393,6 +393,12 @@ button.btn::after {
   color: #ffd487;
 }
 
+.tag-danger {
+  background: rgba(255, 91, 111, 0.18);
+  border: 1rpx solid rgba(255, 108, 128, 0.42);
+  color: #ffdce1;
+}
+
 .chip-group {
   display: flex;
   flex-wrap: wrap;

miniprogram/pages/batch/index.js

@@ -66,5 +66,18 @@ Page({
         '测试报告我已经同步到项目群。'
       ].join('\n')
     })
+  },
+
+  showTokenWeight(e) {
+    const token = e.currentTarget.dataset.token
+    const weight = e.currentTarget.dataset.weight
+    const weightNum = Number(weight || 0)
+    const direction = weightNum >= 0 ? '倾向垃圾判定' : '倾向正常判定'
+    wx.showModal({
+      title: '关键词权重',
+      content: `关键词"${token}"\n权重贡献：${weightNum >= 0 ? '+' : ''}${weightNum.toFixed(4)}\n(${direction})`,
+      showCancel: false,
+      confirmText: '关闭'
+    })
   }
 })

miniprogram/pages/batch/index.wxml

@@ -69,6 +69,12 @@
       <view class="progress-track">
         <view class="{{item.prediction === 'spam' ? 'progress-fill' : 'progress-fill-safe'}}" style="width: {{item.confidence_text}};"></view>
       </view>
+      <view class="field" wx:if="{{item.reason_tokens && item.reason_tokens.length}}">
+        <text class="field-label">风险关键词</text>
+        <view class="chip-group">
+          <text class="tag tag-danger" wx:for="{{item.reason_tokens}}" wx:for-item="tokenItem" wx:key="token" data-token="{{tokenItem.token}}" data-weight="{{tokenItem.weight}}" bindtap="showTokenWeight">{{tokenItem.token}}</text>
+        </view>
+      </view>
     </view>
   </view>
 </view>

miniprogram/pages/detect/index.js

@@ -98,5 +98,18 @@ Page({
 
   gotoHistory() {
     wx.navigateTo({ url: '/pages/history/index' })
+  },
+
+  showTokenWeight(e) {
+    const token = e.currentTarget.dataset.token
+    const weight = e.currentTarget.dataset.weight
+    const weightNum = Number(weight || 0)
+    const direction = weightNum >= 0 ? '倾向垃圾判定' : '倾向正常判定'
+    wx.showModal({
+      title: '关键词权重',
+      content: `关键词"${token}"\n权重贡献：${weightNum >= 0 ? '+' : ''}${weightNum.toFixed(4)}\n(${direction})`,
+      showCancel: false,
+      confirmText: '关闭'
+    })
   }
 })

miniprogram/pages/detect/index.wxml

@@ -75,7 +75,7 @@
     <view class="field" wx:if="{{result.detect.reason_tokens && result.detect.reason_tokens.length}}">
       <text class="field-label">风险关键词</text>
       <view class="chip-group">
-        <text class="tag" wx:for="{{result.detect.reason_tokens}}" wx:key="*this">{{item}}</text>
+        <text class="tag tag-danger" wx:for="{{result.detect.reason_tokens}}" wx:key="token" data-token="{{item.token}}" data-weight="{{item.weight}}" bindtap="showTokenWeight">{{item.token}}</text>
       </view>
     </view>