diff --git a/src/blackboard/db.py b/src/blackboard/db.py
index 1e46d40..f9b131c 100644
--- a/src/blackboard/db.py
+++ b/src/blackboard/db.py
@@ -95,6 +95,7 @@ def _migrate_v28(conn: sqlite3.Connection) -> None:
                     next_capability TEXT,
                     stage TEXT,
                     stages_json TEXT DEFAULT '[]',
+                    round_count INTEGER DEFAULT 0,
                     archived INTEGER DEFAULT 0,
                     archived_at TEXT
                 );
@@ -113,6 +114,9 @@ def _migrate_v28(conn: sqlite3.Connection) -> None:
             if fk_was_on:
                 conn.execute("PRAGMA foreign_keys = ON")
 
+    _safe_add_column(conn, "tasks", "round_count", "INTEGER DEFAULT 0")
+    _safe_add_column(conn, "tasks", "resumed_from", "TEXT")
+
     # 3. checkpoints 表（M3）
     conn.execute("""CREATE TABLE IF NOT EXISTS checkpoints (
         id TEXT PRIMARY KEY,
@@ -264,6 +268,7 @@ _SCHEMA_STATEMENTS = [
         next_capability TEXT,
         stage TEXT,
         stages_json TEXT DEFAULT '[]',
+        round_count INTEGER DEFAULT 0,
         resumed_from TEXT
     )""",
     "CREATE INDEX IF NOT EXISTS idx_tasks_status ON tasks(status)",