style(auth): satisfy Biome in password digest helpers

Unescape dollar signs inside character classes and use template literals
instead of string concatenation in the salted digest tests.

src/lib/auth/password.test.ts

@@ -169,36 +169,36 @@ describe("isCombinedDigestOf", () => {
 describe("isSaltedDigestOf", () => {
 	it("verifies md5(salt+password) with hash:salt layout", async () => {
 		const salt = "pepper123";
-		const stored = `${await md5Hex(salt + "oldpass")}:${salt}`;
+		const stored = `${await md5Hex(`${salt}oldpass`)}:${salt}`;
 		expect(await isSaltedDigestOf("oldpass", stored)).toBe(true);
 		expect(await isSaltedDigestOf("wrong", stored)).toBe(false);
 	});
 
 	it("verifies md5(password+salt) with hash:salt layout", async () => {
 		const salt = "pepper123";
-		const stored = `${await md5Hex("oldpass" + salt)}:${salt}`;
+		const stored = `${await md5Hex(`oldpass${salt}`)}:${salt}`;
 		expect(await isSaltedDigestOf("oldpass", stored)).toBe(true);
 	});
 
 	it("verifies the salt:hash layout", async () => {
 		const salt = "abc123";
-		const stored = `${salt}:${await md5Hex(salt + "oldpass")}`;
+		const stored = `${salt}:${await md5Hex(`${salt}oldpass`)}`;
 		expect(await isSaltedDigestOf("oldpass", stored)).toBe(true);
 		expect(await isSaltedDigestOf("wrong", stored)).toBe(false);
 	});
 
 	it("verifies the hash$salt layout", async () => {
 		const salt = "s0lt_9";
-		const stored = `${await md5Hex("oldpass" + salt)}$s0lt_9`;
+		const stored = `${await md5Hex(`oldpass${salt}`)}$s0lt_9`;
 		expect(await isSaltedDigestOf("oldpass", stored)).toBe(true);
 	});
 
 	it("verifies salted sha1 and sha256 digests", async () => {
 		const salt = "pepper123";
-		const sha1Stored = `${await sha1Hex(salt + "oldpass")}:${salt}`;
+		const sha1Stored = `${await sha1Hex(`${salt}oldpass`)}:${salt}`;
 		expect(await isSaltedDigestOf("oldpass", sha1Stored)).toBe(true);
 
-		const sha256Stored = `${await sha256Hex("oldpass" + salt)}:${salt}`;
+		const sha256Stored = `${await sha256Hex(`oldpass${salt}`)}:${salt}`;
 		expect(await isSaltedDigestOf("oldpass", sha256Stored)).toBe(true);
 	});
 
@@ -268,7 +268,7 @@ describe("checkLogin", () => {
 
 	it("migrates a salted md5 hash to bcrypt (md5(salt+password))", async () => {
 		const salt = "pepper123";
-		const stored = `${await md5Hex(salt + "oldpass")}:${salt}`;
+		const stored = `${await md5Hex(`${salt}oldpass`)}:${salt}`;
 		const res = await checkLogin("oldpass", stored);
 		expect(res.valid).toBe(true);
 		expect(res.upgradedHash).toMatch(/^\$2[aby]\$/);
@@ -279,7 +279,7 @@ describe("checkLogin", () => {
 
 	it("migrates a salted sha256 hash to bcrypt (sha256(salt+password))", async () => {
 		const salt = "abc123";
-		const stored = `${salt}:${await sha256Hex(salt + "oldpass")}`;
+		const stored = `${salt}:${await sha256Hex(`${salt}oldpass`)}`;
 		const res = await checkLogin("oldpass", stored);
 		expect(res.valid).toBe(true);
 		expect(res.upgradedHash).toMatch(/^\$2[aby]\$/);

src/lib/auth/password.ts

@@ -130,7 +130,7 @@ export async function isCombinedDigestOf(
  * sha256, sha512) is tried, and both md5(salt+password) and md5(password+salt)
  * orderings are verified to cover both conventions.
  */
-const SALTED_HASH_DELIMITER_RE = /[:\$@_]/;
+const SALTED_HASH_DELIMITER_RE = /[:$@_]/;
 
 export async function isSaltedDigestOf(
 	password: string,
@@ -140,10 +140,10 @@ export async function isSaltedDigestOf(
 
 	for (const { length, hash: hashFn } of DIGEST_SCHEMES) {
 		const hashFirst = stored.match(
-			new RegExp(`^([a-f0-9]{${length}})[:\$@_](.{1,64})$`, "i"),
+			new RegExp(`^([a-f0-9]{${length}})[:$@_](.{1,64})$`, "i"),
 		);
 		const saltFirst = stored.match(
-			new RegExp(`^(.{1,64})[:\$@_]([a-f0-9]{${length}})$`, "i"),
+			new RegExp(`^(.{1,64})[:$@_]([a-f0-9]{${length}})$`, "i"),
 		);
 		const hashHex = hashFirst?.[1] ?? saltFirst?.[2];
 		const salt = hashFirst?.[2] ?? saltFirst?.[1];