feat: add auth crypto utilities (password hash, JWT, token hash)

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

server/auth.ts

@@ -0,0 +1,44 @@
+import { sign, verify } from 'hono/jwt'
+
+export interface AccessTokenPayload {
+  userId: string
+  role: string
+}
+
+export async function hashPassword(password: string): Promise<string> {
+  return Bun.password.hash(password)
+}
+
+export async function verifyPassword(password: string, hash: string): Promise<boolean> {
+  return Bun.password.verify(password, hash)
+}
+
+export async function signAccessToken(
+  userId: string,
+  role: string,
+  secret: string,
+): Promise<string> {
+  return sign(
+    { userId, role, exp: Math.floor(Date.now() / 1000) + 15 * 60 },
+    secret,
+    'HS256',
+  )
+}
+
+export async function verifyAccessToken(
+  token: string,
+  secret: string,
+): Promise<AccessTokenPayload | null> {
+  try {
+    const payload = await verify(token, secret, 'HS256') as { userId: string; role: string }
+    return { userId: payload.userId, role: payload.role }
+  } catch {
+    return null
+  }
+}
+
+export function hashToken(token: string): string {
+  const hasher = new Bun.CryptoHasher('sha256')
+  hasher.update(token)
+  return hasher.digest('hex')
+}