feat(web): sign-in, first-run setup, app shell and user admin (M1)

- core: AuthSession keeps the access token in memory, refreshes it
  once for all parallel requests (single-flight) and retries them;
  refresh races between tabs are retried, reuse signs out; ApiError
  carries problem+json codes and field errors
- web: TanStack Router with guards — guests go to /login, the bootstrap
  admin to /setup/admin, temporary passwords to /setup/password, admin
  pages by role
- login, setup screens, Classic shell (top bar, role-based sidebar,
  empty player), settings: name, theme, language, password, devices
- users admin: search, role filter, create with a one-time temporary
  password, reset, block, role change, delete as the policy allows;
  audit log for admins
- ru/en strings for auth, admin and error codes; language and theme
  are saved in the profile

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/pages/home.module.css

@@ -0,0 +1,63 @@
+.home {
+  min-height: 100%;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 24px;
+  text-align: center;
+}
+
+.greeting {
+  margin: 0;
+  font-family: var(--font-display);
+  font-size: 24px;
+  font-weight: 600;
+  letter-spacing: -0.01em;
+}
+
+.orb {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 6px;
+  width: 300px;
+  height: 300px;
+  max-width: 70vw;
+  max-height: 70vw;
+  border-radius: 50%;
+  color: #fff;
+  background:
+    radial-gradient(circle at 35% 30%, rgba(156, 198, 255, 0.55), transparent 45%),
+    radial-gradient(circle at 65% 70%, var(--wave-color3), transparent 55%),
+    radial-gradient(circle at 50% 50%, var(--wave-color2), var(--wave-color1) 70%);
+  box-shadow: 0 0 80px rgba(47, 128, 255, 0.35);
+  opacity: 0.85;
+  animation: breathe 6s ease-in-out infinite;
+}
+
+.orbLabel {
+  font-family: var(--font-display);
+  font-size: 18px;
+  font-weight: 600;
+}
+
+@keyframes breathe {
+  50% {
+    transform: scale(1.03);
+  }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .orb {
+    animation: none;
+  }
+}
+
+.soon {
+  max-width: 420px;
+  margin: 0;
+  color: var(--text2);
+  line-height: 1.5;
+}