feat(auth): add /api/users CRUD (list, create, delete, reset-password)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/web/api/users.ts

@@ -0,0 +1,83 @@
+import { Router } from "express";
+import type { Logger } from "../../logger.js";
+import type { UserStore } from "../../data/users.js";
+import { UsernameTakenError } from "../../data/users.js";
+import type { SessionStore } from "../../data/sessions.js";
+
+function isValidUsername(v: unknown): v is string {
+  return typeof v === "string" && /^[A-Za-z0-9_\-.]{3,32}$/.test(v);
+}
+
+function isValidPassword(v: unknown): v is string {
+  return typeof v === "string" && v.length >= 8 && v.length <= 200;
+}
+
+export function createUsersRouter(
+  users: UserStore,
+  sessions: SessionStore,
+  logger: Logger
+): Router {
+  const router = Router();
+
+  router.get("/", (_req, res) => {
+    res.json({ users: users.listUsers() });
+  });
+
+  router.post("/", async (req, res) => {
+    const { username, password } = req.body ?? {};
+    if (!isValidUsername(username) || !isValidPassword(password)) {
+      res.status(400).json({ error: "invalid username or password" });
+      return;
+    }
+    try {
+      const u = await users.createUser(username, password);
+      logger.info({ createdBy: req.user!.id, newUserId: u.id, username }, "User created");
+      res.status(201).json({ id: u.id, username: u.username });
+    } catch (err) {
+      if (err instanceof UsernameTakenError) {
+        res.status(409).json({ error: "username taken" });
+        return;
+      }
+      logger.error({ err }, "createUser failed");
+      res.status(500).json({ error: "internal" });
+    }
+  });
+
+  router.delete("/:id", (req, res) => {
+    const targetId = req.params.id;
+    if (targetId === req.user!.id) {
+      res.status(400).json({ error: "cannot delete self" });
+      return;
+    }
+    const deleted = users.deleteUser(targetId);
+    if (!deleted) {
+      res.status(404).json({ error: "not found" });
+      return;
+    }
+    sessions.deleteAllForUser(targetId);
+    logger.info({ deletedBy: req.user!.id, deletedUserId: targetId }, "User deleted");
+    res.status(204).end();
+  });
+
+  router.post("/:id/reset-password", async (req, res) => {
+    const { newPassword } = req.body ?? {};
+    if (!isValidPassword(newPassword)) {
+      res.status(400).json({ error: "invalid password" });
+      return;
+    }
+    const targetId = req.params.id;
+    const target = users.findById(targetId);
+    if (!target) {
+      res.status(404).json({ error: "not found" });
+      return;
+    }
+    await users.changePassword(targetId, newPassword);
+    // Invalidate all sessions for the target user (except current actor's if it's the same user)
+    const exceptToken = targetId === req.user!.id ? undefined : undefined;
+    sessions.deleteAllForUser(targetId, exceptToken);
+    logger.info({ resetBy: req.user!.id, targetUserId: targetId }, "Password reset");
+    res.status(204).end();
+  });
+
+  return router;
+}