feat(nextcloud-files): Anmeldung per Passwort und im Browser (Zwei-Faktor), Abmelden mit Widerruf

- Anmelde-Client (getapppassword, cloud/user, Widerruf, Login Flow v2 mit fester Abfrageadresse,
  Link aus Basis und Token neu gebaut), Anmeldebremse 3/15 min je Benutzer und 8/30 min je Server,
  Ablaufspeicher für Browser-Anmeldungen (20 min, höchstens 200, eine je Benutzer)
- Kontodienst: Verbinden, Trennen mit Widerruf, Sitzung mit Zugangsschlüssel-Sperre,
  frisch ausgestellte oder ersetzte App-Passwörter bleiben nie verwaist; jeder Kontozugriff
  über forTenant mit Mandant UND Benutzer aus dem Token
- Migration 20261008183000: Spalte ncLoginName (App-Passwort gilt nur für den Anmeldenamen der
  Ausstellung, gemessen mit E-Mail-Anmeldung gegen Nextcloud 34)
- Verbindungsbildschirm und Kontoleiste, Texte de/en, RLS-Inventar fortgeschrieben,
  E2E-Skript e2e-connect.sh

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

apps/web/src/messages/en.json

@@ -2337,6 +2337,46 @@
     "main": {
       "server": "Nextcloud: {host}"
     },
+    "connect": {
+      "title": "Connect to Nextcloud",
+      "expiredNotice": "Your connection to Nextcloud has expired or was revoked in Nextcloud. Please sign in again.",
+      "explanation": "Sign in with your Nextcloud account. Tessera does not store your password; instead it has Nextcloud issue a separate access that you can revoke at any time.",
+      "loginName": "User name or email",
+      "password": "Password",
+      "submit": "Sign in",
+      "submitting": "Signing in …",
+      "or": "or",
+      "browser": "Sign in with the browser",
+      "starting": "Starting …",
+      "browserHint": "For accounts with two-factor authentication",
+      "waiting": {
+        "instruction": "Open the Nextcloud sign-in, log in there and confirm with “Grant access”.",
+        "open": "Open sign-in at Nextcloud",
+        "status": "Waiting for confirmation in Nextcloud …",
+        "cancel": "Cancel"
+      },
+      "errors": {
+        "generic": "Signing in failed. Please try again.",
+        "credentialsOrTwoFactor": "Signing in did not work. Either the user name or password is wrong, or your account uses two-factor authentication. In that case, please sign in with the browser.",
+        "useBrowserLogin": "Nextcloud does not allow password sign-in for this account. Please sign in with the browser.",
+        "tooManyAttempts": "Too many failed attempts. Please wait {minutes, plural, one {# minute} other {# minutes}}.",
+        "nextcloudLocked": "Nextcloud is temporarily blocking requests from the Tessera server. Please try again in {minutes, plural, one {# minute} other {# minutes}}.",
+        "flowExpired": "The sign-in has expired. Please start it again.",
+        "nextcloudUnavailable": "Nextcloud is unreachable or did not answer in time.",
+        "tooManyFlows": "Too many browser sign-ins are running right now. Please try again in a moment."
+      }
+    },
+    "account": {
+      "signedInAs": "Signed in as {name}",
+      "disconnect": "Sign out",
+      "disconnectFailed": "The connection could not be removed. Please try again.",
+      "confirm": {
+        "title": "Disconnect from Nextcloud?",
+        "body": "Tessera forgets the access. Your files in Nextcloud stay unchanged.",
+        "confirm": "Disconnect",
+        "cancel": "Cancel"
+      }
+    },
     "errors": {
       "request": "The request failed. Please try again.",
       "loadStatus": "The state of the Nextcloud connection could not be loaded."