Revamp workspace archive handling with async support, input validation improvements and better session management

src/services/usernamePolicy.js

@@ -0,0 +1,15 @@
+// Keep legacy printable names working, while excluding whitespace, controls,
+// path separators, and URL delimiters that are unsafe/confusing in identifiers.
+const USERNAME_PATTERN = /^[^\p{C}\s\\/@?#%]{3,64}$/u;
+
+export function normalizeUsername(value) {
+    return String(value || "").normalize("NFKC").trim();
+}
+
+export function usernameError(username, label = "Username") {
+    if (!username) return `${label} is required`;
+    if (username.length < 3) return `${label} must be at least 3 characters`;
+    if (username.length > 64) return `${label} must be at most 64 characters`;
+    if (!USERNAME_PATTERN.test(username)) return `${label} may contain letters, numbers, dots, underscores, and hyphens only`;
+    return null;
+}