feat(data): add list_config, task_runs tables and task config columns

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Data/SchemaInitializer.cs

@@ -26,6 +26,32 @@ public static class SchemaInitializer
         cmd.CommandText = sql;
         cmd.ExecuteNonQuery();
         tx.Commit();
+
+        ApplyMigrations(conn);
+    }
+
+    private static void ApplyMigrations(SqliteConnection conn)
+    {
+        string[] alterStatements =
+        [
+            "ALTER TABLE tasks ADD COLUMN model TEXT NULL",
+            "ALTER TABLE tasks ADD COLUMN system_prompt TEXT NULL",
+            "ALTER TABLE tasks ADD COLUMN agent_path TEXT NULL",
+        ];
+
+        foreach (var sql in alterStatements)
+        {
+            try
+            {
+                using var cmd = conn.CreateCommand();
+                cmd.CommandText = sql;
+                cmd.ExecuteNonQuery();
+            }
+            catch (SqliteException ex) when (ex.SqliteErrorCode == 1)
+            {
+                // Column already exists — safe to ignore.
+            }
+        }
     }
 
     private static string LoadScript()