diff --git a/docs/design/architecture-v2.6.md b/docs/design/architecture-v2.6.md
index 6c78f81..b29a5cf 100644
--- a/docs/design/architecture-v2.6.md
+++ b/docs/design/architecture-v2.6.md
@@ -275,14 +275,17 @@ CREATE TABLE IF NOT EXISTS comments (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     task_id TEXT NOT NULL,
     author TEXT NOT NULL,                   -- agent id 或 'user'
+    comment_type TEXT NOT NULL DEFAULT 'general',  -- general/handoff/observation/rebuttal/rebuttal_response/debate_argument/debate_rebuttal/debate_judgment
     body TEXT NOT NULL,
     mentions TEXT,                          -- JSON array: ["zhangfei-dev", "guanyu-dev"]
     created_at TEXT NOT NULL DEFAULT (datetime('now')),
 
-    FOREIGN KEY (task_id) REFERENCES tasks(id)
+    FOREIGN KEY (task_id) REFERENCES tasks(id),
+    CHECK (comment_type IN ('general', 'handoff', 'observation', 'rebuttal', 'rebuttal_response', 'debate_argument', 'debate_rebuttal', 'debate_judgment'))
 );
 
 CREATE INDEX IF NOT EXISTS idx_comments_task ON comments(task_id);
+CREATE INDEX IF NOT EXISTS idx_comments_type ON comments(task_id, comment_type);
 CREATE INDEX IF NOT EXISTS idx_comments_author ON comments(author);
 -- 注意:mentions 是 JSON 数组,无法直接建索引。daemon tick 查询用 json_each(mentions)。
 -- 数据量小时够用,后续可拆 comment_mentions 关联表优化。