英语语法两书全覆盖:213 知识点

- 提取 DK《English for Everyone Grammar Guide》与 Murphy《English Grammar
  in Use》完整目录,去重融合成 144 个补充知识点,与既有 69 核心课合计 213
- 补充课为中文为主六步课文(目标/规则/例句/易错/即时练习/知识卡),按
  A1-C1 标注难度,归入入门/基础/进阶三档
- point_id 放宽到 191 以容纳长 slug

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/seed-grammar-extra.ts

@@ -0,0 +1,51 @@
+// 增量种子:把 extra/batch0-3.json 的补充课文写入 grammar_point(不重复,序号续接)
+import fs from "node:fs";
+import path from "node:path";
+import { sql, eq } from "drizzle-orm";
+import { drizzle } from "drizzle-orm/mysql2";
+import mysql from "mysql2/promise";
+import { grammarPoints } from "../src/db/schema";
+
+type Extra = { id: string; title: string; cefr: string; difficulty: number; summary: string; md: string };
+
+const levelOf = (cefr: string) =>
+  cefr === "A1" ? { level: "starter", name: "入门" } : cefr === "A2" ? { level: "base", name: "基础" } : { level: "pro", name: "进阶" };
+
+async function main() {
+  const conn = await mysql.createConnection(process.env.DATABASE_URL!);
+  const db = drizzle(conn);
+
+  const [mx] = await db.select({ m: sql<number>`COALESCE(MAX(seq),0)` }).from(grammarPoints);
+  let seq = mx.m;
+
+  const existing = new Set((await db.select({ pointId: grammarPoints.pointId }).from(grammarPoints)).map((r) => r.pointId));
+
+  let added = 0;
+  for (const f of ["batch0.json", "batch1.json", "batch2.json", "batch3.json"]) {
+    const p = path.join(process.cwd(), "src/content/grammar/extra", f);
+    if (!fs.existsSync(p)) continue;
+    const arr = JSON.parse(fs.readFileSync(p, "utf8")) as Extra[];
+    for (const e of arr) {
+      if (existing.has(e.id)) continue;
+      seq += 1;
+      const lv = levelOf(e.cefr);
+      await db.insert(grammarPoints).values({
+        pointId: e.id,
+        level: lv.level,
+        levelName: lv.name,
+        title: e.title,
+        difficulty: e.difficulty || 1,
+        summary: e.summary,
+        prereq: "[]",
+        md: e.md,
+        seq,
+      });
+      added++;
+    }
+  }
+  const [tot] = await db.select({ n: sql<number>`COUNT(*)` }).from(grammarPoints);
+  console.log("新增补充课:", added, "| 总知识点:", tot.n);
+  await conn.end();
+}
+
+main();