feat: 1、企微通知中隐藏，CI中打印字段明细，另外将整体输出到企微中的md，在CI控制台中打印出来

2、整段截断，具体改动的字段不可截断
      3、不再区分P0\P1\P2

src/main/java/com/codechecker/redis/analyze/SchemaCheckAnalyzer.java

@@ -10,7 +10,9 @@ import com.codechecker.redis.diff.Severity;
 import com.codechecker.redis.git.GitDiffScanner;
 import com.codechecker.redis.git.GitException;
 import com.codechecker.redis.report.CheckReport;
+import com.codechecker.redis.report.KeyStructureChange;
 import com.codechecker.redis.schema.JavaSchemaExtractor;
+import com.codechecker.redis.schema.SkeletonJsonRenderer;
 import com.codechecker.redis.schema.SourceIndex;
 import com.codechecker.redis.schema.TypeSchema;
 import com.github.javaparser.StaticJavaParser;
@@ -19,6 +21,7 @@ import com.github.javaparser.ast.body.TypeDeclaration;
 
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -92,8 +95,10 @@ public class SchemaCheckAnalyzer {
         JavaSchemaExtractor extractorNew = new JavaSchemaExtractor(newIndex, config.getDetection().getMaxFieldDepth());
         JavaSchemaExtractor extractorOld = new JavaSchemaExtractor(oldIndex, config.getDetection().getMaxFieldDepth());
         SchemaDiffer differ = new SchemaDiffer();
+        SkeletonJsonRenderer skeletonRenderer = new SkeletonJsonRenderer();
 
         List<SchemaChange> allChanges = new ArrayList<>();
+        Map<String, KeyStructureChange> keyChanges = new LinkedHashMap<>();
 
         for (String path : candidates) {
             String newContent = newContents.get(path);
@@ -123,16 +128,31 @@ public class SchemaCheckAnalyzer {
                     TypeSchema oldSchema = extractorOld.extract(ow.getResolvedValueType(), ow.isRootArray());
                     TypeSchema newSchema = extractorNew.extract(nw.getResolvedValueType(), nw.isRootArray());
                     List<SchemaChange> changes = differ.diff(oldSchema, newSchema);
+                    if (changes.isEmpty()) {
+                        continue;
+                    }
                     double confidence = min(nw.getConfidence(), ow.getConfidence(),
                             oldSchema.getConfidence(), newSchema.getConfidence());
                     enrich(changes, nw, confidence);
                     allChanges.addAll(changes);
+                    mergeKeyChange(keyChanges, nw.getResolvedKeyPattern(), changes,
+                            skeletonRenderer.render(oldSchema, protectedPaths(changes),
+                                    SkeletonJsonRenderer.DEFAULT_MAX_LEN),
+                            skeletonRenderer.render(newSchema, protectedPaths(changes),
+                                    SkeletonJsonRenderer.DEFAULT_MAX_LEN));
                 } else if (fileChanged) {
                     SchemaChange c = new SchemaChange(ChangeType.WRITE_POINT_ADDED);
                     c.setKeyPattern(nw.getResolvedKeyPattern());
                     c.setWriteLocation(nw.location());
                     c.setMessage("新增 Redis 写入点，value 类型: " + shortType(nw.getResolvedValueType()));
                     allChanges.add(c);
+                    TypeSchema newSchema = extractorNew.extract(nw.getResolvedValueType(), nw.isRootArray());
+                    mergeKeyChange(keyChanges, nw.getResolvedKeyPattern(),
+                            Collections.singletonList(c),
+                            "",
+                            skeletonRenderer.render(newSchema, protectedPaths(
+                                    Collections.singletonList(c)),
+                                    SkeletonJsonRenderer.DEFAULT_MAX_LEN));
                 }
             }
 
@@ -145,13 +165,106 @@ public class SchemaCheckAnalyzer {
                         c.setWriteLocation(ow.location());
                         c.setMessage("删除 Redis 写入点，原 value 类型: " + shortType(ow.getResolvedValueType()));
                         allChanges.add(c);
+                        TypeSchema oldSchema = extractorOld.extract(ow.getResolvedValueType(), ow.isRootArray());
+                        mergeKeyChange(keyChanges, ow.getResolvedKeyPattern(),
+                                Collections.singletonList(c),
+                                skeletonRenderer.render(oldSchema, protectedPaths(
+                                        Collections.singletonList(c)),
+                                        SkeletonJsonRenderer.DEFAULT_MAX_LEN),
+                                "");
                     }
                 }
             }
         }
 
         List<SchemaChange> finalChanges = postProcess(allChanges);
-        return buildReport(oldSha, newSha, finalChanges);
+        // 按最终字段明细重新对齐 key 摘要（过滤被 suppress/dedup 掉的）
+        Map<String, KeyStructureChange> finalKeys = filterKeyChanges(keyChanges, finalChanges);
+        return buildReport(oldSha, newSha, finalChanges, finalKeys);
+    }
+
+    private void mergeKeyChange(Map<String, KeyStructureChange> keyChanges, String keyPattern,
+                                List<SchemaChange> changes, String oldSkeleton, String newSkeleton) {
+        String key = keyPattern == null ? "<unknown>" : keyPattern;
+        KeyStructureChange kc = keyChanges.computeIfAbsent(key, k -> {
+            KeyStructureChange n = new KeyStructureChange();
+            n.setKeyPattern(k);
+            return n;
+        });
+        kc.getFieldDetails().addAll(changes);
+        for (SchemaChange c : changes) {
+            kc.raiseSeverity(c.getSeverity());
+        }
+        if (oldSkeleton != null && !oldSkeleton.isEmpty()) {
+            kc.setOldSkeletonJson(oldSkeleton);
+        }
+        if (newSkeleton != null && !newSkeleton.isEmpty()) {
+            kc.setNewSkeletonJson(newSkeleton);
+        }
+        if (kc.getOldSkeletonJson() == null) {
+            kc.setOldSkeletonJson(oldSkeleton == null ? "" : oldSkeleton);
+        }
+        if (kc.getNewSkeletonJson() == null) {
+            kc.setNewSkeletonJson(newSkeleton == null ? "" : newSkeleton);
+        }
+    }
+
+    private Set<String> protectedPaths(List<SchemaChange> changes) {
+        Set<String> paths = new LinkedHashSet<>();
+        for (SchemaChange c : changes) {
+            if (c.getFieldPath() != null && !c.getFieldPath().isEmpty()) {
+                paths.add(c.getFieldPath());
+            }
+            // 路径迁移时 oldValue 为旧路径
+            if (c.getChangeType() == ChangeType.FIELD_PATH_MOVED
+                    && c.getOldValue() != null && !c.getOldValue().isEmpty()) {
+                paths.add(c.getOldValue());
+            }
+            if (c.getChangeType() == ChangeType.WRAPPER_ADDED
+                    && c.getFieldPath() != null) {
+                paths.add(c.getFieldPath());
+            }
+        }
+        return paths;
+    }
+
+    private Map<String, KeyStructureChange> filterKeyChanges(
+            Map<String, KeyStructureChange> keyChanges, List<SchemaChange> finalChanges) {
+        Set<String> liveKeys = new HashSet<>();
+        for (SchemaChange c : finalChanges) {
+            liveKeys.add(c.getKeyPattern() == null ? "<unknown>" : c.getKeyPattern());
+        }
+        Map<String, KeyStructureChange> result = new LinkedHashMap<>();
+        for (Map.Entry<String, KeyStructureChange> e : keyChanges.entrySet()) {
+            if (liveKeys.contains(e.getKey())) {
+                KeyStructureChange kc = e.getValue();
+                // 仅保留最终明细中仍存在的字段变更
+                List<SchemaChange> retained = new ArrayList<>();
+                Set<String> finalDedup = new HashSet<>();
+                for (SchemaChange c : finalChanges) {
+                    String k = c.getKeyPattern() == null ? "<unknown>" : c.getKeyPattern();
+                    if (!k.equals(e.getKey())) {
+                        continue;
+                    }
+                    String dedupKey = c.getChangeType() + "|" + c.getKeyPattern() + "|"
+                            + c.getWriteLocation() + "|" + c.getFieldPath();
+                    if (finalDedup.add(dedupKey)) {
+                        retained.add(c);
+                    }
+                }
+                kc.getFieldDetails().clear();
+                kc.getFieldDetails().addAll(retained);
+                Severity max = Severity.P2;
+                for (SchemaChange c : retained) {
+                    if (c.getSeverity() != null && c.getSeverity().ordinal() < max.ordinal()) {
+                        max = c.getSeverity();
+                    }
+                }
+                kc.setSeverity(max);
+                result.put(e.getKey(), kc);
+            }
+        }
+        return result;
     }
 
     private void enrich(List<SchemaChange> changes, WritePoint wp, double confidence) {
@@ -208,12 +321,14 @@ public class SchemaCheckAnalyzer {
         return false;
     }
 
-    private CheckReport buildReport(String oldSha, String newSha, List<SchemaChange> changes) {
+    private CheckReport buildReport(String oldSha, String newSha, List<SchemaChange> changes,
+                                    Map<String, KeyStructureChange> keyChanges) {
         CheckReport report = new CheckReport();
         report.setOldSha(oldSha);
         report.setNewSha(newSha);
         report.setMode(config.getMode());
         report.getChanges().addAll(changes);
+        report.getKeyChanges().addAll(keyChanges.values());
 
         boolean blocked = false;
         if (config.isBlockMode()) {

src/main/java/com/codechecker/redis/cli/RedisSchemaCheckerMain.java

@@ -70,13 +70,15 @@ public class RedisSchemaCheckerMain implements Callable<Integer> {
             report.setRepository(repository != null ? repository : root.getFileName().toString());
 
             ReportBuilder builder = new ReportBuilder(config.getNotify().getTitlePrefix());
+            // CI：字段明细 + 完整企微 Markdown
             System.out.println(builder.toConsole(report));
 
             boolean shouldNotify = config.getNotify().isEnabled()
                     && (report.hasChanges() || config.getNotify().isNotifyOnClean());
             if (shouldNotify && !dryRun) {
                 String webhook = config.getNotify().getWebhookUrl();
-                boolean ok = new WeComNotifier().sendMarkdown(webhook, builder.toMarkdown(report));
+                String markdown = builder.toMarkdown(report);
+                boolean ok = new WeComNotifier().sendMarkdown(webhook, markdown);
                 System.out.println("[redis-schema-checker] 企微通知发送: " + (ok ? "成功" : "失败/跳过"));
             }
 

src/main/java/com/codechecker/redis/report/CheckReport.java

@@ -20,11 +20,12 @@ public class CheckReport {
     private String mode;
 
     private final List<SchemaChange> changes = new ArrayList<>();
+    private final List<KeyStructureChange> keyChanges = new ArrayList<>();
     private boolean blocked;
     private int exitCode;
 
     public boolean hasChanges() {
-        return !changes.isEmpty();
+        return !changes.isEmpty() || !keyChanges.isEmpty();
     }
 
     public long count(Severity severity) {
@@ -91,6 +92,10 @@ public class CheckReport {
         return changes;
     }
 
+    public List<KeyStructureChange> getKeyChanges() {
+        return keyChanges;
+    }
+
     public boolean isBlocked() {
         return blocked;
     }

src/main/java/com/codechecker/redis/report/KeyStructureChange.java

@@ -0,0 +1,65 @@
+package com.codechecker.redis.report;
+
+import com.codechecker.redis.diff.SchemaChange;
+import com.codechecker.redis.diff.Severity;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 按 Redis key 聚合后的结构变更摘要（用于企微骨架展示）。
+ */
+public class KeyStructureChange {
+
+    private String keyPattern;
+    private String oldSkeletonJson;
+    private String newSkeletonJson;
+    private Severity severity = Severity.P2;
+    private final List<SchemaChange> fieldDetails = new ArrayList<>();
+
+    public String getKeyPattern() {
+        return keyPattern;
+    }
+
+    public void setKeyPattern(String keyPattern) {
+        this.keyPattern = keyPattern;
+    }
+
+    public String getOldSkeletonJson() {
+        return oldSkeletonJson;
+    }
+
+    public void setOldSkeletonJson(String oldSkeletonJson) {
+        this.oldSkeletonJson = oldSkeletonJson;
+    }
+
+    public String getNewSkeletonJson() {
+        return newSkeletonJson;
+    }
+
+    public void setNewSkeletonJson(String newSkeletonJson) {
+        this.newSkeletonJson = newSkeletonJson;
+    }
+
+    public Severity getSeverity() {
+        return severity;
+    }
+
+    public void setSeverity(Severity severity) {
+        this.severity = severity;
+    }
+
+    public List<SchemaChange> getFieldDetails() {
+        return fieldDetails;
+    }
+
+    public void raiseSeverity(Severity candidate) {
+        if (candidate == null) {
+            return;
+        }
+        if (severity == null || candidate.ordinal() < severity.ordinal()) {
+            // P0=0, P1=1, P2=2 → ordinal 更小更严重
+            severity = candidate;
+        }
+    }
+}

src/main/java/com/codechecker/redis/report/ReportBuilder.java

@@ -10,6 +10,10 @@ import java.util.Map;
 
 /**
  * 将 {@link CheckReport} 渲染为企微 Markdown / 控制台文本。
+ * <ul>
+ *   <li>企微：按 key 展示序列化骨架变更，不含位置/字段明细，不分 P0/P1/P2</li>
+ *   <li>CI：先打字段明细，再完整输出企微 Markdown</li>
+ * </ul>
  */
 public class ReportBuilder {
 
@@ -29,16 +33,60 @@ public class ReportBuilder {
         sb.append("> **提交人**: ").append(nvl(report.getModifier())).append('\n');
         sb.append("> **时间**: ").append(nvl(report.getModifyTime())).append("\n\n");
 
+        List<KeyStructureChange> keys = report.getKeyChanges();
+        if (keys == null || keys.isEmpty()) {
+            // 兼容仅有字段明细时退化展示
+            if (report.getChanges().isEmpty()) {
+                sb.append("未检测到 Redis 序列化结构变更。\n");
+            } else {
+                for (SchemaChange c : report.getChanges()) {
+                    sb.append("- `").append(nvl(c.getKeyPattern())).append("`\n");
+                    if (c.getMessage() != null) {
+                        sb.append("  ").append(c.getMessage()).append('\n');
+                    }
+                }
+            }
+            return sb.toString();
+        }
+
+        for (KeyStructureChange kc : keys) {
+            sb.append("- `").append(nvl(kc.getKeyPattern())).append("`\n");
+            String oldJson = nvl(kc.getOldSkeletonJson());
+            String newJson = nvl(kc.getNewSkeletonJson());
+            if (oldJson.isEmpty() && !newJson.isEmpty()) {
+                sb.append("  value 新增为 “").append(newJson).append("”\n\n");
+            } else if (!oldJson.isEmpty() && newJson.isEmpty()) {
+                sb.append("  value 原结构 “").append(oldJson).append("” 已删除写入\n\n");
+            } else {
+                sb.append("  value 值从 “").append(oldJson).append("”\n");
+                sb.append("  变更为 “").append(newJson).append("”\n\n");
+            }
+        }
+        return sb.toString();
+    }
+
+    /**
+     * CI 控制台：字段明细 + 完整企微 Markdown。
+     */
+    public String toConsole(CheckReport report) {
+        StringBuilder sb = new StringBuilder();
+        if (!report.hasChanges()) {
+            sb.append("未检测到 Redis 序列化结构变更。\n");
+            return sb.toString();
+        }
+
+        sb.append("======== 字段明细 ========\n");
         Map<Severity, List<SchemaChange>> grouped = new EnumMap<>(Severity.class);
         for (SchemaChange c : report.getChanges()) {
             grouped.computeIfAbsent(c.getSeverity(), k -> new ArrayList<>()).add(c);
         }
-
+        boolean anyDetail = false;
         for (Severity severity : Severity.values()) {
             List<SchemaChange> list = grouped.get(severity);
             if (list == null || list.isEmpty()) {
                 continue;
             }
+            anyDetail = true;
             sb.append("### ").append(severity).append('\n');
             for (SchemaChange c : list) {
                 sb.append("- **").append(c.getChangeType().getLabel()).append("**");
@@ -55,12 +103,15 @@ public class ReportBuilder {
             }
             sb.append('\n');
         }
+        if (!anyDetail) {
+            sb.append("（无字段级明细）\n\n");
+        }
+
+        sb.append("======== 企微 Markdown ========\n");
+        sb.append(toMarkdown(report));
         return sb.toString();
     }
 
-    /**
-     * 将详情文案中的 key 加粗，如「删除字段 lastError」→「**删除字段**: lastError」。
-     */
     private String formatDetailMessage(String message) {
         String trimmed = message.trim();
         int colonCn = trimmed.indexOf('：');
@@ -92,13 +143,6 @@ public class ReportBuilder {
         return trimmed;
     }
 
-    public String toConsole(CheckReport report) {
-        if (!report.hasChanges()) {
-            return "未检测到 Redis 序列化结构变更。";
-        }
-        return toMarkdown(report);
-    }
-
     private String shortSha(String sha) {
         if (sha == null) {
             return "";

src/main/java/com/codechecker/redis/schema/SkeletonJsonRenderer.java

@@ -0,0 +1,375 @@
+package com.codechecker.redis.schema;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * 将扁平 {@link TypeSchema} 还原为带占位符的序列化骨架 JSON。
+ * 超长时整段压缩/截断，但受保护（改动）字段路径对应片段不被截断。
+ */
+public class SkeletonJsonRenderer {
+
+    /** 单侧骨架默认最大长度（企微 markdown 总长约 4096）。 */
+    public static final int DEFAULT_MAX_LEN = 1500;
+
+    public String render(TypeSchema schema) {
+        return render(schema, null, Integer.MAX_VALUE);
+    }
+
+    /**
+     * @param protectedPaths 改动相关字段路径（如 vo.dbName、expiresAtMs），压缩时优先保留
+     * @param maxLen         输出最大字符数
+     */
+    public String render(TypeSchema schema, Set<String> protectedPaths, int maxLen) {
+        if (schema == null || schema.isEmpty()) {
+            return "{}";
+        }
+        Set<String> protectedSet = protectedPaths == null
+                ? new LinkedHashSet<>() : new LinkedHashSet<>(protectedPaths);
+        Node root = buildTree(schema);
+        String full = write(root, "", protectedSet, false);
+        if (full.length() <= maxLen) {
+            return full;
+        }
+        String compact = write(root, "", protectedSet, true);
+        if (compact.length() <= maxLen) {
+            return compact;
+        }
+        return truncatePreserve(compact, protectedSet, maxLen);
+    }
+
+    private Node buildTree(TypeSchema schema) {
+        Node root = new Node(JsonType.OBJECT);
+        for (FieldSchema field : schema.getFields().values()) {
+            putPath(root, field.getPath(), field.getJsonType());
+        }
+        // 根数组：字段以 [] / [].xxx 记录
+        if (root.children.size() == 1 && root.children.containsKey("[]")) {
+            Node arr = new Node(JsonType.ARRAY);
+            arr.children.put("[]", root.children.get("[]"));
+            return arr;
+        }
+        return root;
+    }
+
+    private void putPath(Node root, String path, JsonType type) {
+        List<Seg> segs = parsePath(path);
+        if (segs.isEmpty()) {
+            return;
+        }
+        Node cur = root;
+        for (int i = 0; i < segs.size(); i++) {
+            Seg seg = segs.get(i);
+            boolean last = i == segs.size() - 1;
+            if (seg.array) {
+                Node arr = cur.children.computeIfAbsent(seg.name, k -> new Node(JsonType.ARRAY));
+                arr.type = JsonType.ARRAY;
+                Node elem = arr.children.computeIfAbsent("[]", k -> new Node(JsonType.OBJECT));
+                if (last) {
+                    if (type == JsonType.OBJECT || type == JsonType.ARRAY || type == JsonType.MAP) {
+                        elem.type = type;
+                    } else {
+                        elem.type = type;
+                        elem.leaf = true;
+                    }
+                }
+                cur = elem;
+            } else {
+                Node child = cur.children.computeIfAbsent(seg.name,
+                        k -> new Node(last ? type : JsonType.OBJECT));
+                if (last) {
+                    child.type = type;
+                    child.leaf = type != JsonType.OBJECT && type != JsonType.ARRAY && type != JsonType.MAP;
+                } else if (child.type != JsonType.ARRAY) {
+                    child.type = JsonType.OBJECT;
+                }
+                cur = child;
+            }
+        }
+    }
+
+    private List<Seg> parsePath(String path) {
+        List<Seg> segs = new ArrayList<>();
+        if (path == null || path.isEmpty()) {
+            return segs;
+        }
+        for (String raw : path.split("\\.")) {
+            if (raw.isEmpty()) {
+                continue;
+            }
+            if ("[]".equals(raw)) {
+                segs.add(new Seg("[]", false));
+            } else if (raw.endsWith("[]")) {
+                segs.add(new Seg(raw.substring(0, raw.length() - 2), true));
+            } else {
+                segs.add(new Seg(raw, false));
+            }
+        }
+        return segs;
+    }
+
+    private String write(Node node, String pathPrefix, Set<String> protectedPaths, boolean compact) {
+        if (node == null) {
+            return "null";
+        }
+        if (node.type == JsonType.ARRAY) {
+            Node elem = node.children.get("[]");
+            if (elem == null) {
+                return "[]";
+            }
+            String elemPath = pathPrefix.isEmpty() ? "[]" : pathPrefix + "[]";
+            if (compact && !isProtectedUnder(pathPrefix, protectedPaths)
+                    && !isProtectedUnder(elemPath, protectedPaths)) {
+                return "[...]";
+            }
+            return "[" + write(elem, elemPath, protectedPaths, compact) + "]";
+        }
+        if (node.leaf || isScalar(node.type)) {
+            return placeholder(node.type);
+        }
+        if (node.type == JsonType.MAP) {
+            return "{}";
+        }
+
+        StringBuilder sb = new StringBuilder();
+        sb.append('{');
+        boolean first = true;
+        for (Map.Entry<String, Node> e : node.children.entrySet()) {
+            String name = e.getKey();
+            if (name == null || name.isEmpty()) {
+                continue;
+            }
+            Node child = e.getValue();
+            String childPath = pathPrefix.isEmpty() ? name : pathPrefix + "." + name;
+            // 根数组占位名 [] 不作为 JSON key 输出（由上层 ARRAY 处理）
+            if ("[]".equals(name) && pathPrefix.isEmpty()) {
+                continue;
+            }
+
+            if (!first) {
+                sb.append(',');
+            }
+            first = false;
+            sb.append('"').append(escape(name)).append("\":");
+
+            if (compact && !isProtectedUnder(childPath, protectedPaths) && child.type != JsonType.ARRAY) {
+                sb.append(collapsedValue(child));
+            } else if (child.type == JsonType.ARRAY) {
+                sb.append(write(child, childPath, protectedPaths, compact));
+            } else if (child.leaf || isScalar(child.type)) {
+                sb.append(placeholder(child.type));
+            } else {
+                sb.append(write(child, childPath, protectedPaths, compact));
+            }
+        }
+        sb.append('}');
+        return sb.toString();
+    }
+
+    private String collapsedValue(Node child) {
+        if (child.type == JsonType.ARRAY) {
+            return "[...]";
+        }
+        if (child.type == JsonType.OBJECT || child.type == JsonType.MAP) {
+            return "\"...\"";
+        }
+        return placeholder(child.type);
+    }
+
+    private boolean isProtectedUnder(String pathPrefix, Set<String> protectedPaths) {
+        if (protectedPaths == null || protectedPaths.isEmpty() || pathPrefix == null) {
+            return false;
+        }
+        for (String p : protectedPaths) {
+            if (p == null || p.isEmpty()) {
+                continue;
+            }
+            if (p.equals(pathPrefix)) {
+                return true;
+            }
+            if (pathPrefix.isEmpty()) {
+                continue;
+            }
+            if (p.startsWith(pathPrefix + ".") || p.startsWith(pathPrefix + "[")) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private String truncatePreserve(String json, Set<String> protectedPaths, int maxLen) {
+        List<String> fragments = new ArrayList<>();
+        for (String path : protectedPaths) {
+            String key = lastSegment(path);
+            if (key.isEmpty() || "[]".equals(key)) {
+                continue;
+            }
+            String needle = "\"" + key + "\"";
+            int idx = json.indexOf(needle);
+            if (idx < 0) {
+                continue;
+            }
+            int end = findValueEnd(json, idx + needle.length());
+            String frag = json.substring(idx, Math.min(json.length(), end));
+            if (!fragments.contains(frag)) {
+                fragments.add(frag);
+            }
+        }
+
+        StringBuilder kept = new StringBuilder();
+        for (String f : fragments) {
+            if (kept.length() > 0 && kept.length() + f.length() + 1 > maxLen) {
+                // 不截断改动字段：装不下则整段保留已收集的改动片段
+                break;
+            }
+            if (kept.length() > 0) {
+                kept.append(',');
+            }
+            kept.append(f);
+            // 单条改动字段允许超过 maxLen（不可截断）
+            if (fragments.size() == 1 && kept.length() > maxLen) {
+                return kept.toString();
+            }
+        }
+        String focus = kept.toString();
+        if (focus.length() >= maxLen) {
+            return focus;
+        }
+        int markerLen = 20;
+        int budget = maxLen - focus.length() - (focus.isEmpty() ? 0 : markerLen);
+        if (budget < 8) {
+            return focus.isEmpty()
+                    ? json.substring(0, Math.min(maxLen, json.length()))
+                    : "{...(truncated)," + focus + "}";
+        }
+        String head = json.substring(0, Math.min(budget, json.length()));
+        if (focus.isEmpty()) {
+            return head + (json.length() > head.length() ? "..." : "");
+        }
+        return head + "...[改动字段]..." + focus;
+    }
+
+    private int findValueEnd(String json, int afterKey) {
+        int i = afterKey;
+        while (i < json.length() && (json.charAt(i) == ':' || Character.isWhitespace(json.charAt(i)))) {
+            i++;
+        }
+        if (i >= json.length()) {
+            return json.length();
+        }
+        char c = json.charAt(i);
+        if (c == '"') {
+            i++;
+            while (i < json.length()) {
+                char ch = json.charAt(i++);
+                if (ch == '\\' && i < json.length()) {
+                    i++;
+                } else if (ch == '"') {
+                    break;
+                }
+            }
+            return i;
+        }
+        if (c == '{' || c == '[') {
+            int depth = 0;
+            for (; i < json.length(); i++) {
+                char ch = json.charAt(i);
+                if (ch == '{' || ch == '[') {
+                    depth++;
+                } else if (ch == '}' || ch == ']') {
+                    depth--;
+                    if (depth == 0) {
+                        return i + 1;
+                    }
+                } else if (ch == '"') {
+                    i++;
+                    while (i < json.length()) {
+                        char x = json.charAt(i++);
+                        if (x == '\\' && i < json.length()) {
+                            i++;
+                        } else if (x == '"') {
+                            break;
+                        }
+                    }
+                    i--;
+                }
+            }
+            return json.length();
+        }
+        while (i < json.length() && json.charAt(i) != ',' && json.charAt(i) != '}' && json.charAt(i) != ']') {
+            i++;
+        }
+        return i;
+    }
+
+    private String lastSegment(String path) {
+        if (path == null || path.isEmpty()) {
+            return "";
+        }
+        String p = path;
+        if (p.endsWith("[]")) {
+            p = p.substring(0, p.length() - 2);
+        }
+        int dot = p.lastIndexOf('.');
+        String seg = dot >= 0 ? p.substring(dot + 1) : p;
+        if (seg.endsWith("[]")) {
+            seg = seg.substring(0, seg.length() - 2);
+        }
+        return seg.replace("[]", "");
+    }
+
+    private boolean isScalar(JsonType type) {
+        return type == JsonType.STRING || type == JsonType.NUMBER
+                || type == JsonType.BOOLEAN || type == JsonType.UNKNOWN;
+    }
+
+    private String placeholder(JsonType type) {
+        if (type == null) {
+            return "null";
+        }
+        switch (type) {
+            case NUMBER:
+                return "0";
+            case BOOLEAN:
+                return "false";
+            case STRING:
+                return "\"\"";
+            case MAP:
+            case OBJECT:
+                return "{}";
+            case ARRAY:
+                return "[]";
+            case UNKNOWN:
+            default:
+                return "null";
+        }
+    }
+
+    private String escape(String s) {
+        return s.replace("\\", "\\\\").replace("\"", "\\\"");
+    }
+
+    private static final class Seg {
+        final String name;
+        final boolean array;
+
+        Seg(String name, boolean array) {
+            this.name = name;
+            this.array = array;
+        }
+    }
+
+    private static final class Node {
+        JsonType type;
+        boolean leaf;
+        final Map<String, Node> children = new LinkedHashMap<>();
+
+        Node(JsonType type) {
+            this.type = type;
+        }
+    }
+}