feat:

1、多 key 默认拼成 1 条企微通知
2、UTF-8 超过 4096 字节 → 按 key 拆开，每条带完整抬头，依次发送
3、条间间隔 200ms，降低机器人限频风险
4、CI 控制台会标明「超长已按 key 拆为 N 条」并逐条打印

src/test/java/com/codechecker/cache/report/ReportBuilderTest.java

@@ -7,6 +7,7 @@ import org.junit.jupiter.api.Test;
 
 import java.util.Collections;
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Set;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -55,11 +56,15 @@ class ReportBuilderTest {
 
         String md = new ReportBuilder("[缓存结构变更]").toMarkdown(report);
 
+        // Key：颜色 + 行内代码（与 ReportBuilder.appendKeyLine 一致）
         assertTrue(md.contains(
-                "- Key --> <font color=\"warning\">`saas:period-config:migration:current`</font>"));
+                "- <font color=\"warning\">`Key --> saas:period-config:migration:current`</font>"));
+
+        int oldSection = md.indexOf("> **value值由：**");
+        int newSection = md.indexOf("> **变更为：**");
+        assertTrue(oldSection >= 0, "应包含「value值由」段落，实际 markdown:\n" + md);
+        assertTrue(newSection > oldSection, "应包含「变更为」段落且在旧值之后，实际 markdown:\n" + md);
 
-        int oldSection = md.indexOf("value 值从");
-        int newSection = md.indexOf("变更为");
         String oldPart = md.substring(oldSection, newSection);
         String newPart = md.substring(newSection);
 
@@ -126,6 +131,8 @@ class ReportBuilderTest {
         assertTrue(console.contains("======== 字段明细 ========"));
         assertTrue(console.contains("**删除字段**: x"));
         assertTrue(console.contains("<font color=\"warning\">\"x\":\"\"</font>"));
+        assertTrue(console.contains("> **value值由：**"));
+        assertTrue(console.contains("> **变更为：**"));
         assertFalse(console.contains("`{\"x\":\"\"}`"));
     }
 
@@ -138,4 +145,77 @@ class ReportBuilderTest {
         assertTrue(out.contains("<font color=\"warning\">\"dbName\":\"\"</font>"));
         assertFalse(out.contains("<font color=\"warning\">\"id\":\"\"</font>"));
     }
+
+    @Test
+    void multipleSmallKeysStayInOneWeComMessage() {
+        CheckReport report = baseReport();
+        report.getKeyChanges().add(simpleKey("k-a", "{\"a\":\"\"}", "{\"a\":\"\",\"x\":\"\"}", "x"));
+        report.getKeyChanges().add(simpleKey("k-b", "{\"b\":\"\"}", "{\"b\":\"\",\"y\":\"\"}", "y"));
+
+        List<String> messages = new ReportBuilder("[缓存结构变更]").toWeComMessages(report);
+        assertEquals(1, messages.size());
+        assertTrue(messages.get(0).contains("k-a"));
+        assertTrue(messages.get(0).contains("k-b"));
+        assertTrue(ReportBuilder.utf8Bytes(messages.get(0)) <= ReportBuilder.WECOM_MARKDOWN_MAX_BYTES);
+    }
+
+    @Test
+    void oversizedMultiKeysSplitOneMessagePerKey() {
+        CheckReport report = baseReport();
+        // 两侧骨架各约 1.8KB，两条拼在一起超 4096；单条仍应落在上限内
+        String fat = fatJson(1800);
+        report.getKeyChanges().add(simpleKey("fat-key-1", fat, fat + "1", null));
+        report.getKeyChanges().add(simpleKey("fat-key-2", fat, fat + "2", null));
+
+        List<String> messages = new ReportBuilder("[缓存结构变更]").toWeComMessages(report);
+        assertEquals(2, messages.size(), "超长应按 key 拆成 2 条");
+        assertTrue(messages.get(0).contains("fat-key-1"));
+        assertFalse(messages.get(0).contains("fat-key-2"));
+        assertTrue(messages.get(1).contains("fat-key-2"));
+        assertFalse(messages.get(1).contains("fat-key-1"));
+        assertTrue(ReportBuilder.utf8Bytes(messages.get(0)) <= ReportBuilder.WECOM_MARKDOWN_MAX_BYTES);
+        assertTrue(ReportBuilder.utf8Bytes(messages.get(1)) <= ReportBuilder.WECOM_MARKDOWN_MAX_BYTES);
+        // 抬头在每条中重复
+        assertTrue(messages.get(0).contains("## [缓存结构变更] jnpf-java-cloud"));
+        assertTrue(messages.get(1).contains("## [缓存结构变更] jnpf-java-cloud"));
+
+        String console = new ReportBuilder("[缓存结构变更]").toConsole(report);
+        assertTrue(console.contains("超长已按 key 拆为 2 条"));
+    }
+
+    private static CheckReport baseReport() {
+        CheckReport report = new CheckReport();
+        report.setRepository("jnpf-java-cloud");
+        report.setBranch("feature/x");
+        report.setOldSha("aaa11111");
+        report.setNewSha("bbb22222");
+        report.setModifier("dongzi");
+        report.setModifyTime("2026-07-14 12:00:00");
+        return report;
+    }
+
+    private static KeyStructureChange simpleKey(String pattern, String oldJson, String newJson,
+                                               String addedField) {
+        KeyStructureChange key = new KeyStructureChange();
+        key.setKeyPattern(pattern);
+        key.setOldSkeletonJson(oldJson);
+        key.setNewSkeletonJson(newJson);
+        if (addedField != null) {
+            SchemaChange added = new SchemaChange(ChangeType.FIELD_ADDED);
+            added.setFieldPath(addedField);
+            added.setKeyPattern(pattern);
+            key.getFieldDetails().add(added);
+            // 保证 hasChanges / 控制台字段明细有数据
+        }
+        return key;
+    }
+
+    private static String fatJson(int minChars) {
+        StringBuilder sb = new StringBuilder("{\"pad\":\"");
+        while (sb.length() < minChars) {
+            sb.append('x');
+        }
+        sb.append("\"}");
+        return sb.toString();
+    }
 }