refactor(feishu): drop dead helper, allow configurable card header, tidy regex

mateclaw-server/src/main/java/vip/mate/channel/feishu/FeishuCardFormatter.java

@@ -19,7 +19,7 @@ final class FeishuCardFormatter {
     private static final Pattern HEADER    = Pattern.compile("(?m)^#{1,6}\\s");
     private static final Pattern TABLE_SEP = Pattern.compile("(?m)^\\|[\\s|:-]+\\|\\s*$");
     private static final Pattern JSON_CODE_BLOCK =
-            Pattern.compile("(?s)```(?:json)?\\s*([\\[{][\\s\\S]*?[\\]\\}])\\s*```");
+            Pattern.compile("(?s)```(?:json)?\\s*([\\[{][\\s\\S]*?[\\]}])\\s*```");
 
     private FeishuCardFormatter() {}
 
@@ -68,24 +68,35 @@ final class FeishuCardFormatter {
                 .count();
     }
 
-    private static String extractJsonCodeBlock(String s) {
-        Matcher m = JSON_CODE_BLOCK.matcher(s);
-        return m.find() ? m.group(1).strip() : null;
-    }
-
     // ==================== 渲染层 ====================
 
+    /** Default markdown card header used when the channel doesn't override it. */
+    static final String DEFAULT_MARKDOWN_HEADER = "AI 助手";
+
     static Map<String, Object> render(String content, ContentFormat format) {
+        return render(content, format, DEFAULT_MARKDOWN_HEADER);
+    }
+
+    /**
+     * Renders the card for the given content/format pair. {@code markdownHeader}
+     * controls the title shown above markdown cards — pass null or blank to
+     * suppress the header entirely. JSON and long-text/plain-text layouts ignore
+     * the header (they have never carried one).
+     */
+    static Map<String, Object> render(String content, ContentFormat format, String markdownHeader) {
         return switch (format) {
             case JSON      -> renderJson(content);
-            case MARKDOWN  -> renderMarkdown(content);
+            case MARKDOWN  -> renderMarkdown(content, markdownHeader);
             case LONG_TEXT, PLAIN_TEXT -> renderLongText(content);
         };
     }
 
-    private static Map<String, Object> renderMarkdown(String content) {
+    private static Map<String, Object> renderMarkdown(String content, String headerText) {
+        Map<String, Object> header = (headerText == null || headerText.isBlank())
+                ? null
+                : Map.of("title", Map.of("tag", "plain_text", "content", headerText));
         return cardOf(
-            Map.of("title", Map.of("tag", "plain_text", "content", "AI 助手")),
+            header,
             List.of(Map.of(
                 "tag", "div",
                 "text", Map.of("tag", "lark_md", "content", content)

mateclaw-server/src/main/java/vip/mate/channel/feishu/FeishuChannelAdapter.java

@@ -54,6 +54,7 @@ import java.util.concurrent.TimeUnit;
  * - stale_event_threshold_seconds: 过滤旧事件阈值（默认 30，0 禁用）
  * - card_format: 卡片格式化模式 "auto"（默认）| "always" | "never"
  *               auto: 根据内容自动检测；always: 全部包卡片；never: 全部纯文本（降级/调试用）
+ * - card_header: Markdown 卡片 header 文案，默认 "AI 助手"；设为空串可隐藏 header
  * - require_mention: 群聊中是否需要 @机器人 才响应（默认 false）
  *               true: 仅当消息中 @了机器人才处理；通过飞书 mentions 字段精确判断，无需配置 botPrefix
  *
@@ -1413,7 +1414,8 @@ public class FeishuChannelAdapter extends AbstractChannelAdapter {
 
         boolean preferCard = "always".equals(cardFormat) || fmt != FeishuCardFormatter.ContentFormat.PLAIN_TEXT;
         if (preferCard) {
-            boolean sent = sendCard(targetId, FeishuCardFormatter.render(content, fmt));
+            String cardHeader = getConfigString("card_header", FeishuCardFormatter.DEFAULT_MARKDOWN_HEADER);
+            boolean sent = sendCard(targetId, FeishuCardFormatter.render(content, fmt, cardHeader));
             if (sent) return;
             // Card path bailed (oversized payload, null guard, or network error) —
             // fall through to text so the user doesn't get nothing.