Merge exams grading into homework

Redirect /teacher/exams/grading* to /teacher/homework/submissions; remove exam grading UI/actions/data-access; add homework student workflow and update design docs.

docs/scripts/baseline-migrations.js

@@ -0,0 +1,90 @@
+require("dotenv/config");
+
+const fs = require("node:fs");
+const crypto = require("node:crypto");
+const path = require("node:path");
+const mysql = require("mysql2/promise");
+
+const JOURNAL = {
+  "0000_aberrant_cobalt_man": 1766460456274,
+  "0001_flawless_texas_twister": 1767004087964,
+  "0002_equal_wolfpack": 1767145757594,
+};
+
+function sha256Hex(input) {
+  return crypto.createHash("sha256").update(input).digest("hex");
+}
+
+async function main() {
+  const url = process.env.DATABASE_URL;
+  if (!url) {
+    throw new Error("DATABASE_URL is not set");
+  }
+
+  const conn = await mysql.createConnection(url);
+
+  await conn.query(
+    "CREATE TABLE IF NOT EXISTS `__drizzle_migrations` (id serial primary key, hash text not null, created_at bigint)"
+  );
+
+  const [existing] = await conn.query(
+    "SELECT id, hash, created_at FROM `__drizzle_migrations` ORDER BY created_at DESC LIMIT 1"
+  );
+  if (Array.isArray(existing) && existing.length > 0) {
+    console.log("✅ __drizzle_migrations already has entries. Skip baselining.");
+    await conn.end();
+    return;
+  }
+
+  const [[accountsRow]] = await conn.query(
+    "SELECT COUNT(*) AS cnt FROM information_schema.tables WHERE table_schema=DATABASE() AND table_name='accounts'"
+  );
+  const accountsExists = Number(accountsRow?.cnt ?? 0) > 0;
+  if (!accountsExists) {
+    console.log("ℹ️ No existing tables detected (accounts missing). Skip baselining.");
+    await conn.end();
+    return;
+  }
+
+  const [[structureRow]] = await conn.query(
+    "SELECT COUNT(*) AS cnt FROM information_schema.columns WHERE table_schema=DATABASE() AND table_name='exams' AND column_name='structure'"
+  );
+  const examsStructureExists = Number(structureRow?.cnt ?? 0) > 0;
+
+  const [[homeworkRow]] = await conn.query(
+    "SELECT COUNT(*) AS cnt FROM information_schema.tables WHERE table_schema=DATABASE() AND table_name='homework_assignments'"
+  );
+  const homeworkExists = Number(homeworkRow?.cnt ?? 0) > 0;
+
+  const baselineTags = [];
+  baselineTags.push("0000_aberrant_cobalt_man");
+  if (examsStructureExists) baselineTags.push("0001_flawless_texas_twister");
+  if (homeworkExists) baselineTags.push("0002_equal_wolfpack");
+
+  const drizzleDir = path.resolve(__dirname, "..", "..", "drizzle");
+  for (const tag of baselineTags) {
+    const sqlPath = path.join(drizzleDir, `${tag}.sql`);
+    if (!fs.existsSync(sqlPath)) {
+      throw new Error(`Missing migration file: ${sqlPath}`);
+    }
+    const sqlText = fs.readFileSync(sqlPath).toString();
+    const hash = sha256Hex(sqlText);
+    const createdAt = JOURNAL[tag];
+    if (typeof createdAt !== "number") {
+      throw new Error(`Missing journal timestamp for: ${tag}`);
+    }
+    await conn.query(
+      "INSERT INTO `__drizzle_migrations` (`hash`, `created_at`) VALUES (?, ?)",
+      [hash, createdAt]
+    );
+  }
+
+  console.log(`✅ Baselined __drizzle_migrations: ${baselineTags.join(", ")}`);
+  await conn.end();
+}
+
+main().catch((err) => {
+  console.error("❌ Baseline failed:", err);
+  process.exit(1);
+});
+