security: switch default hashing to Argon2id, fix tests

- hashPassword now uses Argon2id (memory-hard, GPU-resistant) via hash-wasm
- verifyPassword checks both Argon2id and bcrypt
- Legacy hashes (bcrypt, argon2, md5, sha1, sha256, sha512, combined, salted)
  auto-migrate to Argon2id on successful login
- Updated all password tests to expect Argon2id format
- Register validation: min 12 chars, max 128, upper+lower+digit+special required
- Username restricted to [A-Za-z0-9_-], reserved names blocked
- Disposable email domains blocked
- Fixed parameter names for hash-wasm argon2id API (memorySize, iterations, parallelism, hashLength)

src/lib/auth/password.ts

@@ -14,10 +14,10 @@ import { env } from "@/env";
 
 /** Argon2id parameters — memory-hard, GPU-resistant. */
 const ARGON2_CONFIG = {
-	memoryCost: 19456, // ~19 MiB
-	timeCost: 2,
+	memorySize: 19456, // ~19 MiB
+	iterations: 2,
 	parallelism: 1,
-	outputLen: 32,
+	hashLength: 32,
 };
 
 /** Hash new passwords with Argon2id (best practice 2024+). */
@@ -210,6 +210,7 @@ export async function verifyPassword(
 	password: string,
 	stored: string,
 ): Promise<boolean> {
+	if (/^\$argon2/.test(stored)) return isArgon2Of(password, stored);
 	return isBcryptOf(password, stored);
 }