Update admin theme/layout and refresh README details.

Align the project baseline with the latest admin interface styling and layout structure while documenting setup and usage updates in README.

apps/web/src/modules/auth/store/authSessionHint.ts

@@ -0,0 +1,24 @@
+const AUTH_HINT_KEY = "compton-auth-hint";
+const PROTECTED_PATH_PREFIXES = ["/admin", "/profile"] as const;
+
+export function markAuthSessionHint(): void {
+  sessionStorage.setItem(AUTH_HINT_KEY, "1");
+}
+
+export function clearAuthSessionHint(): void {
+  sessionStorage.removeItem(AUTH_HINT_KEY);
+}
+
+export function hasAuthSessionHint(): boolean {
+  return sessionStorage.getItem(AUTH_HINT_KEY) === "1";
+}
+
+export function isProtectedAppPath(pathname: string): boolean {
+  return PROTECTED_PATH_PREFIXES.some(
+    (prefix) => pathname === prefix || pathname.startsWith(`${prefix}/`)
+  );
+}
+
+export function shouldAttemptAuthRefresh(pathname = window.location.pathname): boolean {
+  return hasAuthSessionHint() || isProtectedAppPath(pathname);
+}