新增 SQL 题型：SQLite 内联判题（不依赖外部沙箱）

- SQL 作为语言接入现有提交流程，judge_task 按 language 分流到 SQLJudgeDispatcher
- judge/sql_runner.py：内存 SQLite 判题核心，查询题比结果集/增删改题比表状态，
  authorizer + progress_handler + max_page_count 三重防护
- dispatcher 提取 _process_judge_result/_push_status 供 SQL 判题复用（行为不变）
- 测试点通道支持 1.sql..N.sql 压缩包，出题只需数据脚本+标准答案
- Problem 增加 sql_config 字段；options 数据迁移注册 SQL 语言

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

judge/sql_dispatcher.py

@@ -0,0 +1,101 @@
+"""SQL 题判题调度：不走 JudgeServer 沙箱，在 dramatiq worker 内用 sqlite3 直接判题。
+
+复用 JudgeDispatcher 的 _process_judge_result 完成状态聚合、统计、排名和 WebSocket 推送，
+因此比赛排名、rejudge、题目统计的语义与沙箱判题完全一致。
+"""
+
+import json
+import logging
+import os
+
+from django.conf import settings
+
+from judge.dispatcher import JudgeDispatcher
+from judge.sql_runner import SQLCaseError, run_case
+from submission.models import JudgeStatus, Submission
+from utils.shortcuts import natural_sort_key
+
+logger = logging.getLogger(__name__)
+
+
+class SQLProblemConfigError(Exception):
+    pass
+
+
+class SQLJudgeDispatcher(JudgeDispatcher):
+    def judge(self):
+        Submission.objects.filter(id=self.submission.id).update(result=JudgeStatus.JUDGING)
+        self._push_status(JudgeStatus.JUDGING, "judging")
+
+        try:
+            ref_sql, mode, order_sensitive, init_scripts = self._load_problem_config()
+        except SQLProblemConfigError as e:
+            self._system_error(str(e))
+            return
+
+        cases = []
+        for index, init_sql in enumerate(init_scripts, start=1):
+            try:
+                case = run_case(
+                    init_sql,
+                    ref_sql,
+                    self.submission.code,
+                    mode=mode,
+                    order_sensitive=order_sensitive,
+                    time_limit_ms=self.problem.time_limit,
+                    memory_limit_mb=self.problem.memory_limit,
+                )
+            except SQLCaseError as e:
+                # 初始化/标准答案执行失败，属出题配置问题
+                self._system_error(e.message)
+                return
+            case["test_case"] = str(index)
+            # 语法错误与数据无关，首个测试点即可确认，整题按编译错误处理（ACM 不罚时，前端展示 err_info）
+            if index == 1 and case["result"] == JudgeStatus.COMPILE_ERROR:
+                self._process_judge_result({"err": "CompileError", "data": case["error_message"]})
+                return
+            cases.append(case)
+
+        self._process_judge_result({"err": None, "data": cases})
+
+    def _system_error(self, message):
+        logger.error(f"SQL judge system error, submission {self.submission.id}, problem {self.problem.id}: {message}")
+        Submission.objects.filter(id=self.submission.id).update(result=JudgeStatus.SYSTEM_ERROR, statistic_info={"err_info": message})
+        self._push_status(JudgeStatus.SYSTEM_ERROR, "error")
+
+    def _load_problem_config(self):
+        """校验并加载 SQL 题配置，返回 (标准答案, mode, order_sensitive, 各测试点初始化脚本)。"""
+        sql_config = self.problem.sql_config or {}
+        mode = sql_config.get("mode")
+        if mode not in ("query", "modify"):
+            raise SQLProblemConfigError("题目缺少 SQL 配置（题型）")
+
+        ref_sql = None
+        for item in self.problem.answers or []:
+            if item.get("language") == "SQL" and item.get("code", "").strip():
+                ref_sql = item["code"]
+                break
+        if not ref_sql:
+            raise SQLProblemConfigError("题目缺少 SQL 标准答案")
+
+        test_case_dir = os.path.join(settings.TEST_CASE_DIR, self.problem.test_case_id)
+        try:
+            with open(os.path.join(test_case_dir, "info"), encoding="utf-8") as f:
+                info = json.load(f)
+        except (OSError, json.JSONDecodeError) as e:
+            raise SQLProblemConfigError(f"测试点信息读取失败: {e}")
+        if not info.get("sql"):
+            raise SQLProblemConfigError("测试点不是 SQL 类型，请重新上传 SQL 测试点压缩包")
+
+        init_scripts = []
+        # 按 "1","2",… 自然序遍历，保证与 test_case_score 的下标对应（OI 计分依赖顺序）
+        for key in sorted(info["test_cases"].keys(), key=natural_sort_key):
+            input_name = info["test_cases"][key]["input_name"]
+            try:
+                with open(os.path.join(test_case_dir, input_name), encoding="utf-8") as f:
+                    init_scripts.append(f.read())
+            except OSError as e:
+                raise SQLProblemConfigError(f"测试点脚本 {input_name} 读取失败: {e}")
+        if not init_scripts:
+            raise SQLProblemConfigError("题目没有任何测试点")
+        return ref_sql, mode, sql_config.get("order_sensitive", False), init_scripts