feat(阶段1): drizzle schema 从本地库生成并剪掉 Django 框架表

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

apps/api/drizzle.config.ts

@@ -0,0 +1,12 @@
+import { defineConfig } from "drizzle-kit"
+
+export default defineConfig({
+  dialect: "postgresql",
+  schema: "./src/db/schema.ts",
+  out: "./src/db",
+  dbCredentials: {
+    url: process.env.DATABASE_URL ?? "postgres://onlinejudge:onlinejudge@localhost:5433/onlinejudge",
+  },
+  // Django 框架表不进新后端，introspect 时直接排除
+  tablesFilter: ["!django_*", "!auth_*"],
+})