V 1.3.0 Anmeldung per Passkey (WebAuthn)

Passkey-Login wie in ausgaben-next/werte-next: auf der Login-Seite "Mit
Passkey anmelden", Verwaltung der eigenen Passkeys unter /einstellungen
(Button oben rechts). Das Passwort bleibt als Alternative bestehen.

- lib/webauthn.ts, lib/passkeys.ts sowie API-Routen unter /api/passkey
- proxy.ts: /api/passkey/authenticate ohne Session erreichbar
- Styles als eigene CSS-Klassen in globals.css (kein Tailwind in diesem
  Projekt), passend zum vorhandenen login-*/app-*-Schema
- Tabelle tabletten_passkeys in der DB medizin: app-spezifischer Name,
  damit sich Apps desselben Stacks nicht gegenseitig Passkeys anzeigen
  oder loeschen
- RP-Konfiguration ueber TABLETTEN_RP_*, da sich die .env auf dem Server
  mit anderen Apps teilt, die RP_ID/RP_ORIGIN bereits belegen

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/globals.css

@@ -146,9 +146,22 @@ main {
 .app-logout-bar {
   display: flex;
   justify-content: flex-end;
+  align-items: center;
+  gap: 8px;
   margin-bottom: -2px;
 }
 
+.btn-settings {
+  padding: 8px 16px;
+  background-color: #85B7D7;
+  color: black;
+  font-size: 0.875rem;
+  border-radius: 8px;
+  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
+  text-decoration: none;
+}
+.btn-settings:hover { background-color: #6a9fc5; }
+
 .btn-logout {
   padding: 8px 16px;
   background-color: #dc2626;
@@ -314,3 +327,140 @@ main {
 }
 .login-footer a { color: #2563eb; }
 .login-footer a:hover { text-decoration: underline; }
+
+/* ---------- Passkeys / Anmeldung per Passkey ---------- */
+
+.login-divider {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  margin: 20px 0;
+  color: #9ca3af;
+  font-size: 0.75rem;
+}
+.login-divider::before,
+.login-divider::after {
+  content: "";
+  flex: 1;
+  height: 1px;
+  background: #e5e7eb;
+}
+
+.login-passkey-btn {
+  width: 100%;
+  padding: 8px 16px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 8px;
+  background: none;
+  color: #111827;
+  font-weight: 500;
+  font-size: 0.875rem;
+  border: 2px solid #9ca3af;
+  border-radius: 8px;
+  cursor: pointer;
+}
+.login-passkey-btn:hover:not(:disabled) { border-color: #3b82f6; }
+.login-passkey-btn:disabled { opacity: 0.5; cursor: not-allowed; }
+
+.login-error-passkey { margin-top: 16px; }
+
+.settings-title {
+  margin: 0 0 16px;
+  font-size: 1.25rem;
+  font-weight: 600;
+}
+.settings-back { margin-top: 20px; font-size: 0.875rem; }
+
+.passkeys { max-width: 28rem; }
+.passkeys-title {
+  margin: 0 0 4px;
+  font-size: 0.875rem;
+  font-weight: 600;
+}
+.passkeys-hint {
+  margin: 0 0 12px;
+  font-size: 0.75rem;
+  color: #6b7280;
+}
+.passkeys-empty {
+  margin: 0 0 12px;
+  font-size: 0.875rem;
+  color: #6b7280;
+}
+
+.passkeys-list {
+  list-style: none;
+  margin: 0 0 16px;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+.passkeys-item {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 12px;
+  padding: 8px 12px;
+  background: white;
+  border: 2px solid #d1d5db;
+  border-radius: 8px;
+}
+.passkeys-item-info { min-width: 0; }
+.passkeys-item-label {
+  font-size: 0.875rem;
+  font-weight: 500;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+.passkeys-item-meta { font-size: 0.75rem; color: #6b7280; }
+.passkeys-remove {
+  flex-shrink: 0;
+  padding: 4px 8px;
+  background: none;
+  border: none;
+  color: #dc2626;
+  font-size: 0.75rem;
+  cursor: pointer;
+}
+.passkeys-remove:hover { color: #991b1b; }
+
+.passkeys-add {
+  display: flex;
+  align-items: flex-end;
+  gap: 8px;
+}
+.passkeys-add-field { flex: 1; }
+.passkeys-add-label {
+  display: block;
+  margin-bottom: 4px;
+  font-size: 0.75rem;
+  font-weight: 500;
+}
+.passkeys-input {
+  width: 100%;
+  padding: 8px 12px;
+  background: white;
+  border: 2px solid #9ca3af;
+  border-radius: 8px;
+  font-size: 0.875rem;
+}
+.passkeys-input:focus { border-color: #3b82f6; outline: none; }
+.passkeys-add-btn {
+  flex-shrink: 0;
+  padding: 8px 16px;
+  background-color: #85B7D7;
+  color: black;
+  font-weight: 500;
+  font-size: 0.875rem;
+  border: none;
+  border-radius: 8px;
+  cursor: pointer;
+}
+.passkeys-add-btn:hover:not(:disabled) { background-color: #6a9fc5; }
+.passkeys-add-btn:disabled { opacity: 0.5; cursor: not-allowed; }
+
+.passkeys-error { margin-top: 12px; }