feat: overhaul groups management, remove global team_admin and isolate group administration

BRAIN.md

@@ -31,13 +31,14 @@
 - [x] **Ersteinrichtung (First-Boot Setup Wizard), Echter Login & Einladungscodes (`SetupAndAuthView.tsx`, `server.go`, `sqlite.go`):**
   - Kein hartcodierter Auto-Seed-Benutzer (`admin@mindsift.local` / `"Sandro"`) und kein automatischer `quickStart`-Login mehr beim Seitenaufruf.
   - Beim ersten Start (`0` Benutzer in der Datenbank) erkennt `GET /api/v1/auth/status` automatisch `needsSetup: true` und zeigt den **Ersteinrichtungs-Assistenten** (`POST /api/v1/auth/setup`) zum Anlegen des ersten Server-Admin-Kontos und der Instanz-Grundeinstellungen.
-  - Öffentliche Selbstregistrierung ist standardmäßig deaktiviert (`allowRegistration: false`). Neue Benutzer können nur über einen **Einladungscode** (`MS-XXXXXXXX`, Tabelle `user_invites`) oder direkt durch einen Admin (`admin` / `team_admin`) angelegt werden.
+  - Öffentliche Selbstregistrierung ist standardmäßig deaktiviert (`allowRegistration: false`). Neue Benutzer können nur über einen **Einladungscode** (`MS-XXXXXXXX`, Tabelle `user_invites`) oder direkt durch einen Admin (`admin`) angelegt werden.
-- [x] **Profile-Dropdown & Vollbild-Einstellungsseiten statt kleinem Modal (`App.tsx`, `UserSettingsView.tsx`, `AdminSettingsView.tsx`):**
+- [x] **Profile-Dropdown & Vollbild-Einstellungsseiten (`App.tsx`, `UserSettingsView.tsx`, `GroupsView.tsx`, `AdminSettingsView.tsx`):**
   - Klick auf den Benutzer oben rechts öffnet ein eckiges, monochromes Dropdown-Menü:
     - **Kontoeinstellungen** (`UserSettingsView.tsx` — Vollbild-Ansicht für Profil & Passwort, Darstellung & Themes, Multi-Channel-Alarme, Private Webhooks & Daten-Export).
-    - **Administration** (`AdminSettingsView.tsx` — nur sichtbar für `admin` und `team_admin`; Vollbild-Ansicht für Benutzer, Rollen, Einladungscodes, Organisationen & Teams, Server-Isolation und SMTP-Mailserver).
+    - **Gruppen** (`GroupsView.tsx` — für alle Benutzer; Self-Service Erstellung und Verwaltung von Gruppen, Mitgliedern und Rollen).
+    - **Administration** (`AdminSettingsView.tsx` — nur sichtbar für `admin`; Vollbild-Ansicht für Benutzer, Einladungscodes, Server-Isolation und SMTP-Mailserver).
     - **Abmelden** (bereinigt JWT-Token und führt zurück zum Login-Bildschirm).
-  - 3-stufiges Rollensystem: `admin` (Server-Admin), `team_admin` (Team-Admin mit Berechtigung zum Einladen und Verwalten von Teams) und `member` (Mitglied).
+  - Klares Rollensystem: Global `admin` (Server-Admin) und `member` (Standard-Benutzer). Innerhalb von Gruppen: `admin` (Gruppen-Admin) und `member` (Gruppen-Mitglied).
   - Layout-Fix im Benutzer-Erstellungsformular (`grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-3` mit `min-w-0`), sodass das Rollen-Dropdown niemals über den Container hinausragt.
 - [x] **Multi-Channel-Alarme: E-Mail (SMTP), Discord & Eigener Webhook (`UserSettingsView.tsx`, `AdminSettingsView.tsx`, `server.go`):**
   - Tab heißt klar **Alarme** mit frei kombinierbaren Zielen (`alarmChannels`: `'email'`, `'discord'`, `'webhook'`).
@@ -178,7 +179,7 @@ MindSift speichert alle Daten lokal und hochperformant in SQLite (`/data/mindsif
 
 1. **`users`**
    - `id TEXT PRIMARY KEY`, `email TEXT UNIQUE`, `password_hash TEXT`, `display_name TEXT`
-   - `role TEXT DEFAULT 'member'` (`admin`, `team_admin`, `member`)
+   - `role TEXT DEFAULT 'member'` (`admin`, `member`)
    - `is_active INTEGER DEFAULT 1`, `created_at DATETIME`, `updated_at DATETIME`
 2. **`system_settings`** (Instanzweite globale Konfiguration, 1 Row mit `id = 'singleton'`)
    - `sharing_mode TEXT DEFAULT 'teams_only'` (`strict_private`, `teams_only`, `open`)
@@ -187,7 +188,7 @@ MindSift speichert alle Daten lokal und hochperformant in SQLite (`/data/mindsif
    - `smtp_host TEXT`, `smtp_port INTEGER`, `smtp_user TEXT`, `smtp_pass TEXT`, `smtp_from TEXT`, `smtp_tls INTEGER`
 3. **`user_invites`** (Einladungscodes für neue Registrierungen)
    - `id TEXT PRIMARY KEY`, `code TEXT UNIQUE` (`MS-XXXXXXXX`), `email TEXT` (optional gebunden)
-   - `role TEXT DEFAULT 'member'`, `team_id TEXT` (optional direkte Team-Zuweisung)
+   - `role TEXT DEFAULT 'member'` (`admin`, `member`)
    - `created_by TEXT`, `used_by TEXT`, `expires_at DATETIME`, `created_at DATETIME`
 4. **`organizations` & `organization_teams` & `team_members`**
    - Strukturierung von Benutzern in Abteilungen, Familien oder Projekt-Teams.

frontend/src/App.tsx

@@ -17,6 +17,7 @@ import {
   Download,
   Smartphone,
   Share,
+  Users,
 } from 'lucide-react';
 import { AuthStatus, DashboardStats, SharedList, Thought, User } from './lib/types';
 import {
@@ -42,12 +43,14 @@ import { SetupAndAuthView } from './features/auth/SetupAndAuthView';
 import { UserSettingsView } from './features/settings/UserSettingsView';
 import { AdminSettingsView } from './features/settings/AdminSettingsView';
 import { HelpView } from './features/help/HelpView';
+import { GroupsView } from './features/teams/GroupsView';
 
 type ActiveTab =
   | 'triage'
   | 'tasks'
   | 'workspace'
   | 'lists'
+  | 'groups'
   | 'user_settings'
   | 'admin_settings'
   | 'help';
@@ -403,13 +406,8 @@ export const App: React.FC = () => {
     );
   }
 
-  const isStaff = user.role === 'admin' || user.role === 'team_admin';
+  const isServerAdmin = user.role === 'admin';
-  const roleLabel =
+  const roleLabel = isServerAdmin ? 'Server-Admin' : 'Mitglied';
-    user.role === 'admin'
-      ? 'Server-Admin'
-      : user.role === 'team_admin'
-      ? 'Team-Admin'
-      : 'Mitglied';
 
   return (
     <div className="min-h-screen bg-canvas text-main flex flex-col font-sans selection:bg-accent/30">
@@ -572,6 +570,20 @@ export const App: React.FC = () => {
                     <span>Kontoeinstellungen</span>
                   </button>
 
+                  <button
+                    onClick={() => {
+                      triggerHaptic(10);
+                      setShowProfileMenu(false);
+                      setActiveTab('groups');
+                    }}
+                    className={`w-full px-3.5 py-2.5 text-left flex items-center gap-2.5 hover:bg-panel-elevated transition-colors ${
+                      activeTab === 'groups' ? 'text-accent font-semibold' : 'text-main'
+                    }`}
+                  >
+                    <Users className="w-4 h-4 text-accent" />
+                    <span>Gruppen</span>
+                  </button>
+
                   <button
                     onClick={handleOpenHelp}
                     className={`w-full px-3.5 py-2.5 text-left flex items-center gap-2.5 hover:bg-panel-elevated transition-colors ${
@@ -582,7 +594,7 @@ export const App: React.FC = () => {
                     <span>Hilfe & Anleitung</span>
                   </button>
 
-                  {isStaff && (
+                  {isServerAdmin && (
                     <button
                       onClick={() => {
                         triggerHaptic(10);
@@ -742,6 +754,13 @@ export const App: React.FC = () => {
               <SharedListsView onRefreshGlobal={refreshAll} currentUser={user} />
             )}
 
+            {activeTab === 'groups' && (
+              <GroupsView
+                currentUser={user}
+                onBack={() => setActiveTab(previousTab || 'triage')}
+              />
+            )}
+
             {activeTab === 'user_settings' && (
               <UserSettingsView
                 currentUser={user}
@@ -755,7 +774,7 @@ export const App: React.FC = () => {
               />
             )}
 
-            {activeTab === 'admin_settings' && isStaff && (
+            {activeTab === 'admin_settings' && isServerAdmin && (
               <AdminSettingsView
                 currentUser={user}
                 onBack={() => setActiveTab('triage')}
@@ -1004,6 +1023,21 @@ export const App: React.FC = () => {
                 <span>Kontoeinstellungen</span>
               </button>
 
+              <button
+                type="button"
+                onClick={() => {
+                  triggerHaptic(10);
+                  setShowMobileProfile(false);
+                  setActiveTab('groups');
+                }}
+                className={`w-full px-3 py-2.5 rounded-btn text-left flex items-center gap-3 hover:bg-panel-elevated transition-colors text-xs cursor-pointer ${
+                  activeTab === 'groups' ? 'text-accent font-semibold bg-panel-elevated' : 'text-main'
+                }`}
+              >
+                <Users className="w-4 h-4 text-accent" />
+                <span>Gruppen</span>
+              </button>
+
               <button
                 type="button"
                 onClick={() => {
@@ -1018,7 +1052,7 @@ export const App: React.FC = () => {
                 <span>Hilfe & Anleitung</span>
               </button>
 
-              {isStaff && (
+              {isServerAdmin && (
                 <button
                   type="button"
                   onClick={() => {

frontend/src/features/settings/AdminSettingsView.tsx

@@ -10,16 +10,13 @@ import {
   Copy,
   Check,
   ArrowLeft,
-  Share2,
   Send,
   AlertCircle,
-  Building2,
   UserPlus,
+  Share2,
 } from 'lucide-react';
 import {
-  Organization,
   SystemSettings,
-  Team,
   User,
   UserInvite,
   UserRole,
@@ -31,7 +28,7 @@ interface AdminSettingsViewProps {
   onBack: () => void;
 }
 
-type AdminSection = 'users' | 'teams' | 'server' | 'smtp';
+type AdminSection = 'users' | 'server' | 'smtp';
 
 export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
   currentUser,
@@ -50,19 +47,11 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
 
   const [inviteEmail, setInviteEmail] = useState('');
   const [inviteRole, setInviteRole] = useState<UserRole>('member');
-  const [inviteTeamId, setInviteTeamId] = useState('');
   const [copiedInviteId, setCopiedInviteId] = useState<string | null>(null);
 
   const [resetPwdUserId, setResetPwdUserId] = useState<string | null>(null);
   const [resetPwdVal, setResetPwdVal] = useState('');
 
-  // --- Teams & Groups State ---
-  const [allTeams, setAllTeams] = useState<Team[]>([]);
-  const [newTeamName, setNewTeamName] = useState('');
-  const [newTeamDesc, setNewTeamDesc] = useState('');
-  const [memberSelectByTeam, setMemberSelectByTeam] = useState<Record<string, string>>({});
-  const [memberRoleByTeam, setMemberRoleByTeam] = useState<Record<string, string>>({});
-
   // --- Server & SMTP Settings State ---
   const [settings, setSettings] = useState<SystemSettings>({
     sharingMode: 'teams_only',
@@ -83,14 +72,12 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
 
   const loadAll = async () => {
     try {
-      const [uList, invList, teamList] = await Promise.all([
+      const [uList, invList] = await Promise.all([
         api.adminGetUsers(),
         api.adminGetInvites(),
-        api.getUserTeams(),
       ]);
       setUsers(uList);
       setInvites(invList);
-      setAllTeams(teamList);
 
       if (isServerAdmin) {
         const sys = await api.adminGetSettings();
@@ -149,7 +136,6 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
       const inv = await api.adminCreateInvite({
         email: inviteEmail.trim(),
         role: inviteRole,
-        teamId: inviteTeamId,
       });
       setInvites((prev) => [inv, ...prev]);
       setInviteEmail('');
@@ -231,64 +217,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
     }
   };
 
-  // ============================================================================
-  // HANDLERS: TEAMS & GRUPPEN
-  // ============================================================================
-  const handleCreateTeam = async (e: React.FormEvent) => {
-    e.preventDefault();
-    if (!newTeamName.trim()) return;
-    setStatusMsg(null);
-    try {
-      const created = await api.createTeam(
-        newTeamName.trim(),
-        newTeamDesc.trim()
-      );
-      setNewTeamName('');
-      setNewTeamDesc('');
-      await loadAll();
-      setStatusMsg({ type: 'ok', text: `Gruppe / Team "${created.name}" wurde erstellt.` });
-    } catch (err: any) {
-      setStatusMsg({ type: 'err', text: err.message });
-    }
-  };
 
-  const handleDeleteTeam = async (team: Team) => {
-    if (!window.confirm(`Gruppe / Team "${team.name}" wirklich löschen?`)) return;
-    setStatusMsg(null);
-    try {
-      await api.deleteTeam(team.id);
-      await loadAll();
-      setStatusMsg({ type: 'ok', text: `Gruppe / Team "${team.name}" gelöscht.` });
-    } catch (err: any) {
-      setStatusMsg({ type: 'err', text: err.message });
-    }
-  };
-
-  const handleAddMemberToTeam = async (teamId: string) => {
-    const selectedUserId = memberSelectByTeam[teamId];
-    if (!selectedUserId) return;
-    const role = memberRoleByTeam[teamId] || 'member';
-    setStatusMsg(null);
-    try {
-      await api.addTeamMember(teamId, { userId: selectedUserId, role });
-      setMemberSelectByTeam((prev) => ({ ...prev, [teamId]: '' }));
-      await loadAll();
-      setStatusMsg({ type: 'ok', text: 'Mitglied zur Gruppe hinzugefügt.' });
-    } catch (err: any) {
-      setStatusMsg({ type: 'err', text: err.message });
-    }
-  };
-
-  const handleRemoveMemberFromTeam = async (teamId: string, userId: string) => {
-    setStatusMsg(null);
-    try {
-      await api.removeTeamMember(teamId, userId);
-      await loadAll();
-      setStatusMsg({ type: 'ok', text: 'Mitglied aus Gruppe entfernt.' });
-    } catch (err: any) {
-      setStatusMsg({ type: 'err', text: err.message });
-    }
-  };
 
   // ============================================================================
   // HANDLERS: SERVER & SMTP SETTINGS
@@ -327,9 +256,6 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
     }
   };
 
-  // All teams for invite dropdown
-  const flattenedTeams: Team[] = allTeams;
-
   return (
     <div className="w-full space-y-4">
       {/* Top Page Header */}
@@ -346,17 +272,15 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
           <div>
             <h1 className="text-base font-bold text-main tracking-tight flex items-center gap-2">
               <Shield className="w-4 h-4 text-accent" />
-              <span>Administration & Team-Steuerung</span>
+              <span>Server-Administration</span>
             </h1>
             <p className="text-xs text-muted">
-              Benutzerverwaltung, Einladungscodes, Organisationen, Teams, Isolationsmodus & Mail-Server
+              Benutzerverwaltung, Einladungscodes, Isolationsmodus & Mail-Server
             </p>
           </div>
         </div>
 
-        <span className="badge-accent">
+        <span className="badge-accent">Server-Administrator</span>
-          {isServerAdmin ? 'Server-Administrator' : 'Team-Administrator'}
-        </span>
       </div>
 
       {statusMsg && (
@@ -401,21 +325,6 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
             </div>
           </button>
 
-          <button
-            onClick={() => setSection('teams')}
-            className={`w-full px-3.5 py-3 text-left text-xs font-medium flex items-center gap-2.5 transition-colors ${
-              section === 'teams'
-                ? 'bg-panel-elevated text-main border-l-2 border-l-accent'
-                : 'text-muted hover:text-main hover:bg-canvas/50'
-            }`}
-          >
-            <Users className="w-4 h-4 text-accent flex-shrink-0" />
-            <div>
-              <p className="font-semibold">Teams & Gruppen</p>
-              <p className="text-[10px] text-faint">Familie, Arbeit, Freunde zum Teilen</p>
-            </div>
-          </button>
-
           {isServerAdmin && (
             <>
               <button
@@ -520,8 +429,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
                         className="w-full min-w-0 h-8 px-2 input-field bg-panel"
                       >
                         <option value="member">Mitglied (Standard)</option>
-                        <option value="team_admin">Team-Admin (Darf einladen)</option>
+                        <option value="admin">Server-Admin (Vollzugriff)</option>
-                        {isServerAdmin && <option value="admin">Server-Admin (Vollzugriff)</option>}
                       </select>
                     </div>
                   </div>
@@ -546,7 +454,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
                 </h3>
 
                 <form onSubmit={handleCreateInvite} className="space-y-3">
-                  <div className="grid grid-cols-1 sm:grid-cols-3 gap-3">
+                  <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
                     <div className="min-w-0">
                       <label className="block text-muted mb-1">
                         Gebundene E-Mail (optional)
@@ -561,33 +469,14 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
                     </div>
 
                     <div className="min-w-0">
-                      <label className="block text-muted mb-1">Zugewiesene Rolle</label>
+                      <label className="block text-muted mb-1">Zugewiesene Server-Rolle</label>
                       <select
                         value={inviteRole}
                         onChange={(e) => setInviteRole(e.target.value as UserRole)}
                         className="w-full min-w-0 h-8 px-2 input-field bg-panel"
                       >
                         <option value="member">Mitglied</option>
-                        <option value="team_admin">Team-Admin</option>
+                        <option value="admin">Server-Admin</option>
-                        {isServerAdmin && <option value="admin">Server-Admin</option>}
-                      </select>
-                    </div>
-
-                    <div className="min-w-0">
-                      <label className="block text-muted mb-1">
-                        Automatisch Team zuweisen (optional)
-                      </label>
-                      <select
-                        value={inviteTeamId}
-                        onChange={(e) => setInviteTeamId(e.target.value)}
-                        className="w-full min-w-0 h-8 px-2 input-field bg-panel"
-                      >
-                        <option value="">Kein direktes Team</option>
-                        {flattenedTeams.map((t) => (
-                          <option key={t.id} value={t.id}>
-                            {t.name}
-                          </option>
-                        ))}
                       </select>
                     </div>
                   </div>
@@ -690,8 +579,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
                             title="Benutzerrolle ändern"
                           >
                             <option value="member">Mitglied</option>
-                            <option value="team_admin">Team-Admin</option>
+                            <option value="admin">Server-Admin</option>
-                            {isServerAdmin && <option value="admin">Server-Admin</option>}
                           </select>
 
                           {isServerAdmin && (
@@ -758,203 +646,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
             </div>
           )}
 
-          {/* ================================================================= */}
-          {/* SECTION 2: TEAMS & GRUPPEN */}
-          {/* ================================================================= */}
-          {section === 'teams' && (
-            <div className="space-y-6">
-              <div className="border-b border-border pb-3">
-                <h2 className="text-sm font-bold text-main">Teams & Gruppen verwalten</h2>
-                <p className="text-muted mt-0.5">
-                  Erstelle Gruppen wie Familie, Arbeit oder Freunde. So kannst du Notizen und Listen
-                  direkt für eine gesamte Gruppe freigeben, ohne jeden Benutzer einzeln auswählen zu müssen.
-                </p>
-              </div>
 
-              {/* Create Team/Group Card */}
-              <div className="p-4 bg-canvas border border-border rounded-card space-y-3">
-                <h3 className="font-bold text-main flex items-center gap-2">
-                  <Plus className="w-4 h-4 text-accent" />
-                  <span>Neue Gruppe / Neues Team anlegen</span>
-                </h3>
-                <form onSubmit={handleCreateTeam} className="space-y-3">
-                  <div className="grid grid-cols-1 sm:grid-cols-2 gap-3">
-                    <div>
-                      <label className="block text-muted text-[11px] mb-1 font-medium">
-                        Name der Gruppe / des Teams *
-                      </label>
-                      <input
-                        type="text"
-                        value={newTeamName}
-                        onChange={(e) => setNewTeamName(e.target.value)}
-                        placeholder="z. B. Familie, Arbeit, Freunde…"
-                        required
-                        className="w-full h-8 px-2.5 input-field text-xs"
-                      />
-                    </div>
-                    <div>
-                      <label className="block text-muted text-[11px] mb-1 font-medium">
-                        Beschreibung (optional)
-                      </label>
-                      <input
-                        type="text"
-                        value={newTeamDesc}
-                        onChange={(e) => setNewTeamDesc(e.target.value)}
-                        placeholder="z. B. Gemeinsame Einkaufslisten & Haushaltsnotizen…"
-                        className="w-full h-8 px-2.5 input-field text-xs"
-                      />
-                    </div>
-                  </div>
-                  <div className="flex justify-end">
-                    <button type="submit" className="btn-primary h-8 px-4 text-xs flex items-center gap-1.5">
-                      <Plus className="w-3.5 h-3.5" />
-                      <span>Gruppe / Team anlegen</span>
-                    </button>
-                  </div>
-                </form>
-              </div>
-
-              {/* Teams & Groups List */}
-              <div className="space-y-4">
-                <div className="flex items-center justify-between">
-                  <h3 className="font-bold text-main text-xs uppercase tracking-wider text-muted">
-                    Bestehende Gruppen & Teams ({allTeams.length})
-                  </h3>
-                </div>
-
-                {allTeams.length === 0 ? (
-                  <div className="p-8 bg-canvas border border-border rounded-card text-center space-y-2">
-                    <Users className="w-8 h-8 text-faint mx-auto opacity-50" />
-                    <p className="text-muted text-xs font-medium">Noch keine Teams oder Gruppen vorhanden.</p>
-                    <p className="text-faint text-[11px]">
-                      Lege oben deine erste Gruppe an (z. B. &quot;Familie&quot; oder &quot;Arbeit&quot;), um Notizen und Listen gemeinsam zu nutzen.
-                    </p>
-                  </div>
-                ) : (
-                  allTeams.map((team) => {
-                    const members = Array.isArray(team.members) ? team.members : [];
-                    const availableUsers = users.filter(
-                      (u) => !members.some((m) => m.userId === u.id)
-                    );
-                    return (
-                      <div
-                        key={team.id}
-                        className="p-4 bg-canvas border border-border rounded-card space-y-4"
-                      >
-                        <div className="flex items-start justify-between gap-3 border-b border-border pb-3">
-                          <div className="flex items-start gap-2.5">
-                            <div className="w-8 h-8 rounded-btn bg-accent/10 text-accent flex items-center justify-center flex-shrink-0 mt-0.5">
-                              <Users className="w-4 h-4" />
-                            </div>
-                            <div>
-                              <div className="flex items-center gap-2">
-                                <span className="font-bold text-sm text-main">{team.name}</span>
-                                <span className="text-[11px] px-1.5 py-0.5 rounded-full bg-panel-elevated text-muted border border-border">
-                                  {members.length} {members.length === 1 ? 'Mitglied' : 'Mitglieder'}
-                                </span>
-                              </div>
-                              {team.description && (
-                                <p className="text-xs text-muted mt-1">
-                                  {team.description}
-                                </p>
-                              )}
-                            </div>
-                          </div>
-                          <button
-                            onClick={() => handleDeleteTeam(team)}
-                            className="btn-icon btn-icon-danger"
-                            title="Gruppe / Team löschen"
-                          >
-                            <Trash2 className="w-4 h-4" />
-                          </button>
-                        </div>
-
-                        {/* Members Chips */}
-                        <div className="space-y-2">
-                          <p className="text-[11px] font-semibold text-muted">
-                            Mitglieder ({members.length}):
-                          </p>
-                          {members.length === 0 ? (
-                            <p className="text-[11px] text-faint">
-                              Noch keine Mitglieder in dieser Gruppe.
-                            </p>
-                          ) : (
-                            <div className="flex flex-wrap gap-2">
-                              {members.map((m) => (
-                                <div
-                                  key={m.userId}
-                                  className="px-2.5 py-1 bg-panel border border-border rounded-btn flex items-center gap-2 text-xs"
-                                >
-                                  <span className="text-main font-medium">
-                                    {m.displayName}
-                                  </span>
-                                  <span className="text-[10px] text-muted">
-                                    ({m.role === 'team_admin' ? 'Gruppen-Admin' : 'Mitglied'})
-                                  </span>
-                                  <button
-                                    onClick={() => handleRemoveMemberFromTeam(team.id, m.userId)}
-                                    className="text-faint hover:text-status-err font-bold ml-0.5"
-                                    title="Aus Gruppe entfernen"
-                                  >
-                                    ×
-                                  </button>
-                                </div>
-                              ))}
-                            </div>
-                          )}
-                        </div>
-
-                        {/* Add User to Team Row */}
-                        <div className="pt-3 border-t border-border flex flex-wrap items-center gap-2">
-                          <select
-                            value={memberSelectByTeam[team.id] || ''}
-                            onChange={(e) =>
-                              setMemberSelectByTeam((prev) => ({
-                                ...prev,
-                                [team.id]: e.target.value,
-                              }))
-                            }
-                            className="flex-1 min-w-[200px] h-8 px-2.5 input-field text-xs bg-panel"
-                          >
-                            <option value="">Benutzer auswählen zum Hinzufügen…</option>
-                            {availableUsers.map((u) => (
-                              <option key={u.id} value={u.id}>
-                                {u.displayName} ({u.email})
-                              </option>
-                            ))}
-                          </select>
-
-                          <select
-                            value={memberRoleByTeam[team.id] || 'member'}
-                            onChange={(e) =>
-                              setMemberRoleByTeam((prev) => ({
-                                ...prev,
-                                [team.id]: e.target.value,
-                              }))
-                            }
-                            className="h-8 px-2.5 input-field text-xs bg-panel"
-                          >
-                            <option value="member">Mitglied</option>
-                            <option value="team_admin">Gruppen-Admin</option>
-                          </select>
-
-                          <button
-                            type="button"
-                            onClick={() => handleAddMemberToTeam(team.id)}
-                            disabled={!memberSelectByTeam[team.id]}
-                            className="btn-action h-8 px-3 text-xs flex items-center gap-1.5 disabled:opacity-40"
-                          >
-                            <UserPlus className="w-3.5 h-3.5" />
-                            <span>Hinzufügen</span>
-                          </button>
-                        </div>
-                      </div>
-                    );
-                  })
-                )}
-              </div>
-            </div>
-          )}
 
           {/* ================================================================= */}
           {/* SECTION 3: SERVER & SHARING-ISOLATION (SERVER-ADMIN ONLY) */}

frontend/src/features/settings/UserSettingsView.tsx

@@ -236,8 +236,6 @@ export const UserSettingsView: React.FC<UserSettingsViewProps> = ({
   const roleBadgeLabel =
     currentUser.role === 'admin'
       ? 'Server-Admin'
-      : currentUser.role === 'team_admin'
-      ? 'Team-Admin'
       : 'Mitglied';
 
   return (

frontend/src/features/teams/GroupsView.tsx

@@ -0,0 +1,654 @@
+import React, { useEffect, useState } from 'react';
+import {
+  Users,
+  Plus,
+  Trash2,
+  ArrowLeft,
+  Check,
+  AlertCircle,
+  UserPlus,
+  Shield,
+  Pencil,
+  X,
+  LogOut,
+} from 'lucide-react';
+import { Team, User } from '../../lib/types';
+import { api, triggerHaptic } from '../../lib/api';
+import { UserAutocomplete } from '../UserAutocomplete';
+
+interface GroupsViewProps {
+  currentUser: User;
+  onBack: () => void;
+}
+
+export const GroupsView: React.FC<GroupsViewProps> = ({ currentUser, onBack }) => {
+  const [teams, setTeams] = useState<Team[]>([]);
+  const [directoryUsers, setDirectoryUsers] = useState<User[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [statusMsg, setStatusMsg] = useState<{ type: 'ok' | 'err'; text: string } | null>(null);
+
+  // Create Group Modal State
+  const [showCreateModal, setShowCreateModal] = useState(false);
+  const [newGroupName, setNewGroupName] = useState('');
+  const [newGroupDesc, setNewGroupDesc] = useState('');
+  const [creating, setCreating] = useState(false);
+
+  // Edit Group State
+  const [editingTeamId, setEditingTeamId] = useState<string | null>(null);
+  const [editName, setEditName] = useState('');
+  const [editDesc, setEditDesc] = useState('');
+
+  // Add Member State per Team
+  const [selectedUserByTeam, setSelectedUserByTeam] = useState<Record<string, User | null>>({});
+  const [memberRoleByTeam, setMemberRoleByTeam] = useState<Record<string, 'admin' | 'member'>>({});
+
+  const loadData = async () => {
+    try {
+      const [userTeams, allUsers] = await Promise.all([
+        api.getUserTeams(),
+        api.getUsersDirectory().catch(() => []),
+      ]);
+      setTeams(userTeams);
+      setDirectoryUsers(allUsers);
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Laden der Gruppen' });
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  useEffect(() => {
+    loadData();
+  }, []);
+
+  const handleCreateGroup = async (e: React.FormEvent) => {
+    e.preventDefault();
+    const name = newGroupName.trim();
+    if (!name) return;
+
+    setCreating(true);
+    setStatusMsg(null);
+    triggerHaptic(15);
+
+    try {
+      const created = await api.createTeam(name, newGroupDesc.trim());
+      setNewGroupName('');
+      setNewGroupDesc('');
+      setShowCreateModal(false);
+      await loadData();
+      setStatusMsg({ type: 'ok', text: `Gruppe "${created.name}" erfolgreich erstellt.` });
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Erstellen der Gruppe' });
+    } finally {
+      setCreating(false);
+    }
+  };
+
+  const handleStartEdit = (team: Team) => {
+    setEditingTeamId(team.id);
+    setEditName(team.name);
+    setEditDesc(team.description || '');
+  };
+
+  const handleSaveEdit = async (teamId: string) => {
+    const name = editName.trim();
+    if (!name) return;
+
+    setStatusMsg(null);
+    triggerHaptic(10);
+    try {
+      await api.updateTeam(teamId, name, editDesc.trim());
+      setEditingTeamId(null);
+      await loadData();
+      setStatusMsg({ type: 'ok', text: 'Gruppe erfolgreich aktualisiert.' });
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Aktualisieren der Gruppe' });
+    }
+  };
+
+  const handleDeleteTeam = async (team: Team) => {
+    if (!window.confirm(`Gruppe "${team.name}" wirklich löschen? Alle Freigaben für diese Gruppe werden entfernt.`)) {
+      return;
+    }
+    setStatusMsg(null);
+    triggerHaptic(15);
+    try {
+      await api.deleteTeam(team.id);
+      await loadData();
+      setStatusMsg({ type: 'ok', text: `Gruppe "${team.name}" gelöscht.` });
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Löschen der Gruppe' });
+    }
+  };
+
+  const handleAddMember = async (teamId: string) => {
+    const user = selectedUserByTeam[teamId];
+    if (!user) return;
+    const role = memberRoleByTeam[teamId] || 'member';
+
+    setStatusMsg(null);
+    triggerHaptic(10);
+    try {
+      await api.addTeamMember(teamId, { userId: user.id, role });
+      setSelectedUserByTeam((prev) => ({ ...prev, [teamId]: null }));
+      await loadData();
+      setStatusMsg({ type: 'ok', text: `${user.displayName} wurde zur Gruppe hinzugefügt.` });
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Hinzufügen des Mitglieds' });
+    }
+  };
+
+  const handleChangeMemberRole = async (teamId: string, memberUserId: string, newRole: 'admin' | 'member') => {
+    setStatusMsg(null);
+    triggerHaptic(10);
+    try {
+      await api.updateTeamMemberRole(teamId, memberUserId, newRole);
+      await loadData();
+      setStatusMsg({
+        type: 'ok',
+        text: `Rolle erfolgreich zu "${newRole === 'admin' ? 'Gruppen-Admin' : 'Mitglied'}" geändert.`,
+      });
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Ändern der Rolle' });
+    }
+  };
+
+  const handleRemoveMember = async (teamId: string, memberUserId: string, memberName: string) => {
+    const isSelf = memberUserId === currentUser.id;
+    const msg = isSelf
+      ? 'Möchtest du diese Gruppe wirklich verlassen?'
+      : `Mitglied "${memberName}" wirklich aus der Gruppe entfernen?`;
+
+    if (!window.confirm(msg)) return;
+
+    setStatusMsg(null);
+    triggerHaptic(10);
+    try {
+      await api.removeTeamMember(teamId, memberUserId);
+      await loadData();
+      setStatusMsg({
+        type: 'ok',
+        text: isSelf ? 'Du hast die Gruppe verlassen.' : `Mitglied "${memberName}" wurde entfernt.`,
+      });
+    } catch (err: any) {
+      setStatusMsg({ type: 'err', text: err.message || 'Fehler beim Entfernen des Mitglieds' });
+    }
+  };
+
+  // Group teams into managed (admin) and member-only
+  const managedTeams = teams.filter((t) =>
+    (t.members || []).some((m) => m.userId === currentUser.id && m.role === 'admin')
+  );
+
+  const memberTeams = teams.filter(
+    (t) =>
+      (t.members || []).some((m) => m.userId === currentUser.id && m.role === 'member') &&
+      !managedTeams.some((mt) => mt.id === t.id)
+  );
+
+  return (
+    <div className="w-full space-y-5">
+      {/* Page Header */}
+      <div className="flex flex-col sm:flex-row sm:items-center justify-between gap-3 border-b border-border pb-3">
+        <div className="flex items-center gap-3">
+          <button
+            onClick={onBack}
+            className="btn-action h-8 px-2.5 text-xs flex items-center gap-1.5 cursor-pointer"
+            title="Zurück"
+          >
+            <ArrowLeft className="w-3.5 h-3.5" />
+            <span>Zurück</span>
+          </button>
+          <div>
+            <h1 className="text-base font-bold text-main tracking-tight flex items-center gap-2">
+              <Users className="w-4 h-4 text-accent" />
+              <span>Gruppen & Teams</span>
+              <span className="text-xs px-2 py-0.5 rounded-full bg-panel-elevated text-muted border border-border">
+                {teams.length}
+              </span>
+            </h1>
+            <p className="text-xs text-muted mt-0.5">
+              Erstelle und verwalte Gruppen (z. B. Familie, WG oder Projektteams) für gemeinsame Notizen, Aufgaben und Listen.
+            </p>
+          </div>
+        </div>
+
+        <button
+          onClick={() => {
+            triggerHaptic(10);
+            setShowCreateModal(true);
+          }}
+          className="btn-primary h-8 px-3.5 text-xs flex items-center gap-1.5 self-start sm:self-auto cursor-pointer"
+        >
+          <Plus className="w-3.5 h-3.5" />
+          <span>Neue Gruppe</span>
+        </button>
+      </div>
+
+      {/* Status Messages */}
+      {statusMsg && (
+        <div
+          className={`p-3 text-xs flex items-center justify-between gap-2 rounded-card ${
+            statusMsg.type === 'ok' ? 'alert-ok' : 'alert-err'
+          }`}
+        >
+          <div className="flex items-center gap-2">
+            {statusMsg.type === 'ok' ? (
+              <Check className="w-4 h-4 text-accent flex-shrink-0" />
+            ) : (
+              <AlertCircle className="w-4 h-4 text-status-err flex-shrink-0" />
+            )}
+            <span>{statusMsg.text}</span>
+          </div>
+          <button
+            onClick={() => setStatusMsg(null)}
+            className="text-muted hover:text-main text-[11px] cursor-pointer"
+          >
+            Schließen
+          </button>
+        </div>
+      )}
+
+      {/* Modal: Neue Gruppe erstellen */}
+      {showCreateModal && (
+        <div
+          className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-xs p-4 animate-in fade-in duration-150"
+          onClick={() => setShowCreateModal(false)}
+        >
+          <div
+            className="w-full max-w-md bg-panel border border-border rounded-xl shadow-panel p-5 space-y-4 animate-in zoom-in-95 duration-150"
+            onClick={(e) => e.stopPropagation()}
+          >
+            <div className="flex items-center justify-between pb-3 border-b border-border">
+              <div className="flex items-center gap-2">
+                <div className="w-7 h-7 rounded-btn bg-accent/15 text-accent flex items-center justify-center">
+                  <Users className="w-4 h-4" />
+                </div>
+                <h3 className="font-bold text-sm text-main">Neue Gruppe erstellen</h3>
+              </div>
+              <button
+                type="button"
+                onClick={() => setShowCreateModal(false)}
+                className="p-1 text-muted hover:text-main rounded-btn transition-colors cursor-pointer"
+              >
+                <X className="w-4 h-4" />
+              </button>
+            </div>
+
+            <form onSubmit={handleCreateGroup} className="space-y-4">
+              <div>
+                <label className="block text-muted text-xs mb-1 font-medium">
+                  Name der Gruppe *
+                </label>
+                <input
+                  type="text"
+                  value={newGroupName}
+                  onChange={(e) => setNewGroupName(e.target.value)}
+                  placeholder="z. B. Familie, WG, Arbeit, Projekt X…"
+                  required
+                  autoFocus
+                  className="w-full h-8 px-2.5 input-field text-xs"
+                />
+              </div>
+
+              <div>
+                <label className="block text-muted text-xs mb-1 font-medium">
+                  Beschreibung (optional)
+                </label>
+                <input
+                  type="text"
+                  value={newGroupDesc}
+                  onChange={(e) => setNewGroupDesc(e.target.value)}
+                  placeholder="z. B. Gemeinsame Einkaufslisten & Notizen…"
+                  className="w-full h-8 px-2.5 input-field text-xs"
+                />
+              </div>
+
+              <div className="p-3 bg-canvas border border-border rounded-btn text-[11px] text-muted space-y-1">
+                <p className="font-semibold text-main flex items-center gap-1.5">
+                  <Shield className="w-3.5 h-3.5 text-accent" />
+                  <span>Du wirst Gruppen-Admin</span>
+                </p>
+                <p>
+                  Als Ersteller kannst du weitere Mitglieder hinzufügen, Rollen zuweisen und die Gruppe verwalten.
+                </p>
+              </div>
+
+              <div className="flex justify-end gap-2 pt-2 border-t border-border">
+                <button
+                  type="button"
+                  onClick={() => setShowCreateModal(false)}
+                  className="btn-action h-8 px-3 text-xs cursor-pointer"
+                >
+                  Abbrechen
+                </button>
+                <button
+                  type="submit"
+                  disabled={creating || !newGroupName.trim()}
+                  className="btn-primary h-8 px-4 text-xs flex items-center gap-1.5 cursor-pointer disabled:opacity-50"
+                >
+                  <Plus className="w-3.5 h-3.5" />
+                  <span>Gruppe anlegen</span>
+                </button>
+              </div>
+            </form>
+          </div>
+        </div>
+      )}
+
+      {/* Main Content Area */}
+      {loading ? (
+        <div className="p-8 text-center text-muted text-xs">Lade Gruppen…</div>
+      ) : teams.length === 0 ? (
+        <div className="p-10 bg-canvas border border-border rounded-card text-center space-y-3">
+          <div className="w-12 h-12 rounded-full bg-panel-elevated text-muted mx-auto flex items-center justify-center">
+            <Users className="w-6 h-6 text-accent opacity-75" />
+          </div>
+          <div>
+            <h3 className="font-bold text-main text-sm">Noch keine Gruppen vorhanden</h3>
+            <p className="text-muted text-xs mt-1 max-w-md mx-auto">
+              Erstelle deine erste Gruppe, um Aufgaben, Einkaufslisten oder Dokumente gemeinsam mit anderen zu nutzen.
+            </p>
+          </div>
+          <button
+            onClick={() => {
+              triggerHaptic(10);
+              setShowCreateModal(true);
+            }}
+            className="btn-primary h-8 px-4 text-xs inline-flex items-center gap-1.5 cursor-pointer"
+          >
+            <Plus className="w-3.5 h-3.5" />
+            <span>Erste Gruppe anlegen</span>
+          </button>
+        </div>
+      ) : (
+        <div className="space-y-6">
+          {/* SECTION 1: Gruppen, die ich verwalte */}
+          <div className="space-y-3">
+            <div className="flex items-center justify-between">
+              <h2 className="text-xs font-bold text-main uppercase tracking-wider text-muted flex items-center gap-2">
+                <Shield className="w-3.5 h-3.5 text-accent" />
+                <span>Gruppen, die ich verwalte ({managedTeams.length})</span>
+              </h2>
+            </div>
+
+            {managedTeams.length === 0 ? (
+              <div className="p-4 bg-canvas border border-border rounded-card text-xs text-muted">
+                Du bist derzeit noch in keiner Gruppe als Admin eingetragen. Klicke oben auf &quot;Neue Gruppe&quot;, um eine eigene Gruppe zu erstellen.
+              </div>
+            ) : (
+              <div className="space-y-4">
+                {managedTeams.map((team) => {
+                  const members = team.members || [];
+                  const isEditing = editingTeamId === team.id;
+                  const memberUserIds = members.map((m) => m.userId);
+
+                  return (
+                    <div
+                      key={team.id}
+                      className="p-4 bg-canvas border border-border rounded-card space-y-4 shadow-sm"
+                    >
+                      {/* Team Header */}
+                      <div className="flex items-start justify-between gap-3 border-b border-border pb-3">
+                        <div className="flex items-start gap-2.5 flex-1 min-w-0">
+                          <div className="w-8 h-8 rounded-btn bg-accent/15 text-accent flex items-center justify-center flex-shrink-0 mt-0.5">
+                            <Users className="w-4 h-4" />
+                          </div>
+
+                          {isEditing ? (
+                            <div className="flex-1 space-y-2 max-w-lg">
+                              <input
+                                type="text"
+                                value={editName}
+                                onChange={(e) => setEditName(e.target.value)}
+                                placeholder="Gruppenname"
+                                className="w-full h-8 px-2.5 input-field text-xs font-bold"
+                              />
+                              <input
+                                type="text"
+                                value={editDesc}
+                                onChange={(e) => setEditDesc(e.target.value)}
+                                placeholder="Optionale Beschreibung"
+                                className="w-full h-7 px-2.5 input-field text-xs"
+                              />
+                              <div className="flex gap-2">
+                                <button
+                                  type="button"
+                                  onClick={() => handleSaveEdit(team.id)}
+                                  className="btn-primary h-7 px-3 text-[11px] cursor-pointer"
+                                >
+                                  Speichern
+                                </button>
+                                <button
+                                  type="button"
+                                  onClick={() => setEditingTeamId(null)}
+                                  className="btn-action h-7 px-2.5 text-[11px] cursor-pointer"
+                                >
+                                  Abbrechen
+                                </button>
+                              </div>
+                            </div>
+                          ) : (
+                            <div className="min-w-0">
+                              <div className="flex items-center gap-2 flex-wrap">
+                                <span className="font-bold text-sm text-main truncate">
+                                  {team.name}
+                                </span>
+                                <span className="badge-accent text-[10px] py-0.5 px-2">
+                                  Gruppen-Admin
+                                </span>
+                                <span className="text-[11px] px-1.5 py-0.5 rounded-full bg-panel-elevated text-muted border border-border">
+                                  {members.length} {members.length === 1 ? 'Mitglied' : 'Mitglieder'}
+                                </span>
+                              </div>
+                              {team.description && (
+                                <p className="text-xs text-muted mt-1 break-words">
+                                  {team.description}
+                                </p>
+                              )}
+                            </div>
+                          )}
+                        </div>
+
+                        {!isEditing && (
+                          <div className="flex items-center gap-1.5 flex-shrink-0">
+                            <button
+                              onClick={() => handleStartEdit(team)}
+                              className="btn-action h-7 px-2.5 text-xs flex items-center gap-1 cursor-pointer"
+                              title="Gruppe bearbeiten"
+                            >
+                              <Pencil className="w-3.5 h-3.5" />
+                              <span className="hidden sm:inline">Bearbeiten</span>
+                            </button>
+                            <button
+                              onClick={() => handleDeleteTeam(team)}
+                              className="btn-icon btn-icon-danger"
+                              title="Gruppe löschen"
+                            >
+                              <Trash2 className="w-3.5 h-3.5" />
+                            </button>
+                          </div>
+                        )}
+                      </div>
+
+                      {/* Members List */}
+                      <div className="space-y-2">
+                        <p className="text-[11px] font-semibold text-muted uppercase tracking-wider">
+                          Mitglieder ({members.length})
+                        </p>
+                        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-2">
+                          {members.map((m) => {
+                            const isSelf = m.userId === currentUser.id;
+                            const isAdmin = m.role === 'admin';
+
+                            return (
+                              <div
+                                key={m.userId}
+                                className="p-2.5 bg-panel border border-border rounded-btn flex items-center justify-between gap-2 text-xs"
+                              >
+                                <div className="flex items-center gap-2 min-w-0">
+                                  <div className="w-6 h-6 rounded-full bg-accent/20 text-accent text-[10px] font-bold flex items-center justify-center flex-shrink-0">
+                                    {(m.displayName || 'U').slice(0, 1).toUpperCase()}
+                                  </div>
+                                  <div className="min-w-0">
+                                    <p className="text-main font-medium truncate text-xs">
+                                      {m.displayName} {isSelf && <span className="text-faint">(Du)</span>}
+                                    </p>
+                                    <p className="text-[10px] text-muted truncate">
+                                      {m.email}
+                                    </p>
+                                  </div>
+                                </div>
+
+                                <div className="flex items-center gap-1.5 flex-shrink-0">
+                                  <select
+                                    value={m.role}
+                                    onChange={(e) =>
+                                      handleChangeMemberRole(
+                                        team.id,
+                                        m.userId,
+                                        e.target.value as 'admin' | 'member'
+                                      )
+                                    }
+                                    className={`h-6 px-1.5 text-[10px] rounded border ${
+                                      isAdmin
+                                        ? 'bg-accent/15 border-accent/40 text-accent font-semibold'
+                                        : 'bg-canvas border-border text-muted'
+                                    }`}
+                                    title="Rolle ändern"
+                                  >
+                                    <option value="member">Mitglied</option>
+                                    <option value="admin">Gruppen-Admin</option>
+                                  </select>
+
+                                  <button
+                                    onClick={() => handleRemoveMember(team.id, m.userId, m.displayName)}
+                                    className="p-1 text-faint hover:text-status-err rounded transition-colors cursor-pointer"
+                                    title={isSelf ? 'Gruppe verlassen' : 'Mitglied entfernen'}
+                                  >
+                                    <X className="w-3.5 h-3.5" />
+                                  </button>
+                                </div>
+                              </div>
+                            );
+                          })}
+                        </div>
+                      </div>
+
+                      {/* Add Member Row */}
+                      <div className="pt-3 border-t border-border flex flex-col sm:flex-row items-stretch sm:items-center gap-2">
+                        <div className="flex-1 min-w-[220px]">
+                          <UserAutocomplete
+                            users={directoryUsers}
+                            selectedUser={selectedUserByTeam[team.id] || null}
+                            onSelectUser={(u) =>
+                              setSelectedUserByTeam((prev) => ({ ...prev, [team.id]: u }))
+                            }
+                            excludeUserIds={memberUserIds}
+                            placeholder="Benutzer suchen zum Hinzufügen…"
+                          />
+                        </div>
+
+                        <select
+                          value={memberRoleByTeam[team.id] || 'member'}
+                          onChange={(e) =>
+                            setMemberRoleByTeam((prev) => ({
+                              ...prev,
+                              [team.id]: e.target.value as 'admin' | 'member',
+                            }))
+                          }
+                          className="h-8 px-2.5 input-field text-xs bg-panel"
+                        >
+                          <option value="member">Mitglied</option>
+                          <option value="admin">Gruppen-Admin</option>
+                        </select>
+
+                        <button
+                          type="button"
+                          onClick={() => handleAddMember(team.id)}
+                          disabled={!selectedUserByTeam[team.id]}
+                          className="btn-primary h-8 px-3.5 text-xs flex items-center justify-center gap-1.5 cursor-pointer disabled:opacity-40"
+                        >
+                          <UserPlus className="w-3.5 h-3.5" />
+                          <span>Hinzufügen</span>
+                        </button>
+                      </div>
+                    </div>
+                  );
+                })}
+              </div>
+            )}
+          </div>
+
+          {/* SECTION 2: Meine Mitgliedschaften (als Mitglied) */}
+          {memberTeams.length > 0 && (
+            <div className="space-y-3 pt-2">
+              <h2 className="text-xs font-bold text-main uppercase tracking-wider text-muted flex items-center gap-2">
+                <Users className="w-3.5 h-3.5 text-accent" />
+                <span>Meine Mitgliedschaften ({memberTeams.length})</span>
+              </h2>
+
+              <div className="space-y-3">
+                {memberTeams.map((team) => {
+                  const members = team.members || [];
+                  const admins = members.filter((m) => m.role === 'admin');
+
+                  return (
+                    <div
+                      key={team.id}
+                      className="p-4 bg-canvas border border-border rounded-card space-y-3 shadow-sm"
+                    >
+                      <div className="flex items-start justify-between gap-3 border-b border-border pb-3">
+                        <div className="flex items-start gap-2.5">
+                          <div className="w-8 h-8 rounded-btn bg-panel-elevated text-muted flex items-center justify-center flex-shrink-0 mt-0.5">
+                            <Users className="w-4 h-4" />
+                          </div>
+                          <div>
+                            <div className="flex items-center gap-2">
+                              <span className="font-bold text-sm text-main">{team.name}</span>
+                              <span className="text-[11px] px-1.5 py-0.5 rounded-full bg-panel-elevated text-muted border border-border">
+                                {members.length} {members.length === 1 ? 'Mitglied' : 'Mitglieder'}
+                              </span>
+                            </div>
+                            {team.description && (
+                              <p className="text-xs text-muted mt-1">{team.description}</p>
+                            )}
+                          </div>
+                        </div>
+
+                        <button
+                          onClick={() => handleRemoveMember(team.id, currentUser.id, currentUser.displayName)}
+                          className="btn-action text-status-err hover:bg-status-err-bg h-7 px-2.5 text-xs flex items-center gap-1.5 cursor-pointer"
+                          title="Gruppe verlassen"
+                        >
+                          <LogOut className="w-3.5 h-3.5" />
+                          <span>Gruppe verlassen</span>
+                        </button>
+                      </div>
+
+                      {/* Admins & Members list in read-only mode */}
+                      <div className="space-y-1.5">
+                        <p className="text-[11px] font-semibold text-muted">
+                          Gruppen-Admins:{' '}
+                          <span className="text-main font-normal">
+                            {admins.map((a) => a.displayName).join(', ') || 'Keiner'}
+                          </span>
+                        </p>
+                        <p className="text-[11px] font-semibold text-muted">
+                          Alle Mitglieder:{' '}
+                          <span className="text-faint font-normal">
+                            {members.map((m) => m.displayName).join(', ')}
+                          </span>
+                        </p>
+                      </div>
+                    </div>
+                  );
+                })}
+              </div>
+            </div>
+          )}
+        </div>
+      )}
+    </div>
+  );
+};

frontend/src/lib/api.ts

@@ -723,6 +723,13 @@ export const api = {
     });
   },
 
+  async updateTeam(teamId: string, name: string, description = ''): Promise<Team> {
+    return request<Team>(`/api/v1/teams/${teamId}`, {
+      method: 'PUT',
+      body: JSON.stringify({ name, description }),
+    });
+  },
+
   async deleteTeam(teamId: string): Promise<void> {
     await request(`/api/v1/teams/${teamId}`, { method: 'DELETE' });
   },
@@ -742,6 +749,17 @@ export const api = {
     });
   },
 
+  async updateTeamMemberRole(
+    teamId: string,
+    userId: string,
+    role: 'admin' | 'member'
+  ): Promise<void> {
+    await request(`/api/v1/teams/${teamId}/members/${userId}`, {
+      method: 'PUT',
+      body: JSON.stringify({ role }),
+    });
+  },
+
   async removeTeamMember(teamId: string, userId: string): Promise<void> {
     await request(`/api/v1/teams/${teamId}/members/${userId}`, { method: 'DELETE' });
   },

frontend/src/lib/types.ts

@@ -1,6 +1,6 @@
 export type ThoughtStatus = 'inbox' | 'kept' | 'discarded' | 'converted';
 export type PriorityLevel = 'low' | 'normal' | 'high' | 'urgent';
-export type UserRole = 'admin' | 'team_admin' | 'member';
+export type UserRole = 'admin' | 'member';
 
 export interface AuthStatus {
   needsSetup: boolean;
@@ -119,7 +119,7 @@ export interface Organization {
 
 export interface Team {
   id: string;
-  orgId: string;
+  orgId?: string;
   name: string;
   description: string;
   members?: TeamMember[];
@@ -131,7 +131,7 @@ export interface TeamMember {
   userId: string;
   displayName: string;
   email: string;
-  role: 'owner' | 'team_admin' | 'editor' | 'member' | 'viewer';
+  role: 'admin' | 'member';
   joinedAt: string;
 }
 

internal/api/server.go

@@ -150,8 +150,10 @@ func (s *Server) Router() http.Handler {
 		r.Post("/api/v1/organizations/{id}/teams", s.handleCreateOrgTeam)
 		r.Get("/api/v1/teams", s.handleGetUserTeams)
 		r.Post("/api/v1/teams", s.handleCreateTeamDirect)
+		r.Put("/api/v1/teams/{id}", s.handleUpdateTeam)
 		r.Delete("/api/v1/teams/{id}", s.handleDeleteTeam)
 		r.Post("/api/v1/teams/{id}/members", s.handleAddTeamMember)
+		r.Put("/api/v1/teams/{id}/members/{userId}", s.handleUpdateTeamMemberRole)
 		r.Delete("/api/v1/teams/{id}/members/{userId}", s.handleRemoveTeamMember)
 
 		// API Keys Management
@@ -268,8 +270,8 @@ func (s *Server) staffMiddleware(next http.Handler) http.Handler {
 			return
 		}
 		user, err := s.store.GetUserByID(userID)
-		if err != nil || user == nil || (user.Role != "admin" && user.Role != "team_admin") {
+		if err != nil || user == nil || user.Role != "admin" {
-			writeError(w, http.StatusForbidden, "Admin- oder Team-Admin-Berechtigung erforderlich")
+			writeError(w, http.StatusForbidden, "Admin-Berechtigung erforderlich")
 			return
 		}
 		next.ServeHTTP(w, r)
@@ -1829,18 +1831,20 @@ func (s *Server) handleCreateOrgTeam(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	// Automatically add creator to team
-	_ = s.store.AddTeamMember(team.ID, userID, "team_admin")
+	_ = s.store.AddTeamMember(team.ID, userID, "admin")
 	team.Members, _ = s.store.GetTeamMembers(team.ID)
 	writeJSON(w, http.StatusCreated, team)
 }
 
-func (s *Server) handleDeleteTeam(w http.ResponseWriter, r *http.Request) {
+func (s *Server) isTeamAdmin(userID, teamID string) bool {
-	teamID := chi.URLParam(r, "id")
+	if userID == "" || teamID == "" {
-	if err := s.store.DeleteTeam(teamID); err != nil {
+		return false
-		writeError(w, http.StatusInternalServerError, err.Error())
-		return
 	}
-	writeJSON(w, http.StatusOK, map[string]bool{"deleted": true})
+	role, err := s.store.GetTeamMemberRole(teamID, userID)
+	if err != nil {
+		return false
+	}
+	return role == "admin"
 }
 
 func (s *Server) handleCreateTeamDirect(w http.ResponseWriter, r *http.Request) {
@@ -1868,22 +1872,56 @@ func (s *Server) handleCreateTeamDirect(w http.ResponseWriter, r *http.Request)
 		writeError(w, http.StatusBadRequest, err.Error())
 		return
 	}
-	// Automatically add creator to team as team_admin
+	// Automatically add creator to team as group admin
-	_ = s.store.AddTeamMember(team.ID, userID, "team_admin")
+	_ = s.store.AddTeamMember(team.ID, userID, "admin")
 	team.Members, _ = s.store.GetTeamMembers(team.ID)
 	writeJSON(w, http.StatusCreated, team)
 }
 
+func (s *Server) handleUpdateTeam(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
+	teamID := chi.URLParam(r, "id")
+	if !s.isTeamAdmin(userID, teamID) {
+		writeError(w, http.StatusForbidden, "Nur Gruppen-Administratoren können die Gruppe bearbeiten")
+		return
+	}
+	var req struct {
+		Name        string `json:"name"`
+		Description string `json:"description"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "Ungültiges JSON")
+		return
+	}
+	name := strings.TrimSpace(req.Name)
+	if name == "" {
+		writeError(w, http.StatusBadRequest, "Name für das Team / die Gruppe ist erforderlich")
+		return
+	}
+	updated, err := s.store.UpdateTeam(teamID, name, req.Description)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, updated)
+}
+
+func (s *Server) handleDeleteTeam(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
+	teamID := chi.URLParam(r, "id")
+	if !s.isTeamAdmin(userID, teamID) {
+		writeError(w, http.StatusForbidden, "Nur Gruppen-Administratoren können die Gruppe löschen")
+		return
+	}
+	if err := s.store.DeleteTeam(teamID); err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]bool{"deleted": true})
+}
+
 func (s *Server) handleGetUserTeams(w http.ResponseWriter, r *http.Request) {
 	userID := auth.GetUserID(r.Context())
-	user, _ := s.store.GetUserByID(userID)
-	if (r.URL.Query().Get("all") == "true") || (user != nil && (user.Role == "admin" || user.Role == "team_admin")) {
-		teams, err := s.store.GetAllTeams()
-		if err == nil {
-			writeJSON(w, http.StatusOK, teams)
-			return
-		}
-	}
 	teams, err := s.store.GetTeamsForUser(userID)
 	if err != nil {
 		writeError(w, http.StatusInternalServerError, err.Error())
@@ -1893,7 +1931,12 @@ func (s *Server) handleGetUserTeams(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleAddTeamMember(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
 	teamID := chi.URLParam(r, "id")
+	if !s.isTeamAdmin(userID, teamID) {
+		writeError(w, http.StatusForbidden, "Nur Gruppen-Administratoren können Mitglieder hinzufügen")
+		return
+	}
 	var req struct {
 		UserID string `json:"userId"`
 		Email  string `json:"email"`
@@ -1916,7 +1959,39 @@ func (s *Server) handleAddTeamMember(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusBadRequest, "Benutzer-ID oder E-Mail erforderlich")
 		return
 	}
-	if err := s.store.AddTeamMember(teamID, targetUserID, req.Role); err != nil {
+	role := strings.ToLower(strings.TrimSpace(req.Role))
+	if role != "admin" && role != "member" {
+		role = "member"
+	}
+	if err := s.store.AddTeamMember(teamID, targetUserID, role); err != nil {
+		writeError(w, http.StatusBadRequest, err.Error())
+		return
+	}
+	members, _ := s.store.GetTeamMembers(teamID)
+	writeJSON(w, http.StatusOK, members)
+}
+
+func (s *Server) handleUpdateTeamMemberRole(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
+	teamID := chi.URLParam(r, "id")
+	memberUserID := chi.URLParam(r, "userId")
+	if !s.isTeamAdmin(userID, teamID) {
+		writeError(w, http.StatusForbidden, "Nur Gruppen-Administratoren können Mitgliedsrollen ändern")
+		return
+	}
+	var req struct {
+		Role string `json:"role"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "Ungültiges JSON")
+		return
+	}
+	role := strings.ToLower(strings.TrimSpace(req.Role))
+	if role != "admin" && role != "member" {
+		writeError(w, http.StatusBadRequest, "Ungültige Rolle (erlaubt sind: admin, member)")
+		return
+	}
+	if err := s.store.UpdateTeamMemberRole(teamID, memberUserID, role); err != nil {
 		writeError(w, http.StatusBadRequest, err.Error())
 		return
 	}
@@ -1925,10 +2000,20 @@ func (s *Server) handleAddTeamMember(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleRemoveTeamMember(w http.ResponseWriter, r *http.Request) {
+	userID := auth.GetUserID(r.Context())
 	teamID := chi.URLParam(r, "id")
 	memberUserID := chi.URLParam(r, "userId")
+
+	isSelf := userID == memberUserID
+	isAdmin := s.isTeamAdmin(userID, teamID)
+
+	if !isSelf && !isAdmin {
+		writeError(w, http.StatusForbidden, "Nicht berechtigt, dieses Mitglied zu entfernen")
+		return
+	}
+
 	if err := s.store.RemoveTeamMember(teamID, memberUserID); err != nil {
-		writeError(w, http.StatusInternalServerError, err.Error())
+		writeError(w, http.StatusBadRequest, err.Error())
 		return
 	}
 	writeJSON(w, http.StatusOK, map[string]bool{"removed": true})

internal/api/server_test.go

@@ -145,7 +145,7 @@ func TestFirstBootSetupAndInviteRegistrationAndNonNullSlices(t *testing.T) {
 	}
 
 	// 5. Create an Invite as Admin and register with that Invite Code
-	invBody := []byte(`{"role":"team_admin","validDays":7}`)
+	invBody := []byte(`{"role":"admin","validDays":7}`)
 	req = httptest.NewRequest(http.MethodPost, "/api/v1/admin/invites", bytes.NewReader(invBody))
 	req.Header.Set("Authorization", "Bearer "+setupRes.Token)
 	req.Header.Set("Content-Type", "application/json")
@@ -163,7 +163,7 @@ func TestFirstBootSetupAndInviteRegistrationAndNonNullSlices(t *testing.T) {
 	regWithInviteBody, _ := json.Marshal(map[string]string{
 		"email":       "invited@example.com",
 		"password":    "password123",
-		"displayName": "Invited Team Admin",
+		"displayName": "Invited Admin",
 		"inviteCode":  createdInvite.Code,
 	})
 	req = httptest.NewRequest(http.MethodPost, "/api/v1/auth/register", bytes.NewReader(regWithInviteBody))
@@ -177,8 +177,8 @@ func TestFirstBootSetupAndInviteRegistrationAndNonNullSlices(t *testing.T) {
 		User domain.User `json:"user"`
 	}
 	_ = json.Unmarshal(rec.Body.Bytes(), &invitedRes)
-	if invitedRes.User.Role != "team_admin" {
+	if invitedRes.User.Role != "admin" {
-		t.Fatalf("expected invited user to receive role 'team_admin', got %q", invitedRes.User.Role)
+		t.Fatalf("expected invited user to receive role 'admin', got %q", invitedRes.User.Role)
 	}
 }
 

internal/domain/models.go

@@ -98,7 +98,7 @@ type User struct {
 	Username            string   `json:"username,omitempty"`
 	PasswordHash        string   `json:"-"`
 	DisplayName         string   `json:"displayName"`
-	Role                string   `json:"role"` // admin | team_admin | member
+	Role                string   `json:"role"` // admin | member
 	IsActive            bool     `json:"isActive"`
 	AlarmChannels       []string `json:"alarmChannels"` // email | discord | webhook
 	AlarmEmail          string   `json:"alarmEmail"`
@@ -112,7 +112,7 @@ type UserInvite struct {
 	ID        string `json:"id"`
 	Code      string `json:"code"`
 	Email     string `json:"email,omitempty"`
-	Role      string `json:"role"` // member | team_admin | admin
+	Role      string `json:"role"` // member | admin
 	TeamID    string `json:"teamId,omitempty"`
 	TeamName  string `json:"teamName,omitempty"`
 	CreatedBy string `json:"createdBy"`
@@ -212,7 +212,7 @@ type Organization struct {
 
 type Team struct {
 	ID          string       `json:"id"`
-	OrgID       string       `json:"orgId"`
+	OrgID       string       `json:"orgId,omitempty"`
 	Name        string       `json:"name"`
 	Description string       `json:"description"`
 	Members     []TeamMember `json:"members"`
@@ -224,7 +224,7 @@ type TeamMember struct {
 	UserID      string `json:"userId"`
 	DisplayName string `json:"displayName"`
 	Email       string `json:"email"`
-	Role        string `json:"role"` // team_admin | member | owner
+	Role        string `json:"role"` // admin | member
 	JoinedAt    string `json:"joinedAt"`
 }
 

internal/storage/sqlite.go

@@ -178,7 +178,7 @@ func (s *Store) migrate() error {
 	CREATE TABLE IF NOT EXISTS team_members (
 		team_id TEXT NOT NULL,
 		user_id TEXT NOT NULL,
-		role TEXT NOT NULL DEFAULT 'editor',
+		role TEXT NOT NULL DEFAULT 'member',
 		joined_at TEXT NOT NULL,
 		PRIMARY KEY (team_id, user_id),
 		FOREIGN KEY(team_id) REFERENCES teams(id) ON DELETE CASCADE,
@@ -391,6 +391,11 @@ func (s *Store) migrate() error {
 		}
 	}
 
+	// Clean up legacy roles in team_members and users
+	_, _ = s.db.Exec(`UPDATE team_members SET role = 'admin' WHERE role IN ('team_admin', 'owner')`)
+	_, _ = s.db.Exec(`UPDATE team_members SET role = 'member' WHERE role NOT IN ('admin', 'member')`)
+	_, _ = s.db.Exec(`UPDATE users SET role = 'member' WHERE role = 'team_admin'`)
+
 	// Reindex block tags if table is newly added or empty
 	var tagCount int
 	_ = s.db.QueryRow(`SELECT COUNT(*) FROM doc_block_tags`).Scan(&tagCount)
@@ -534,7 +539,7 @@ func (s *Store) CreateUser(email, passwordHash, displayName, role string) (*doma
 }
 
 func (s *Store) CreateUserWithUsername(email, username, passwordHash, displayName, role string) (*domain.User, error) {
-	if role != "admin" && role != "team_admin" && role != "member" {
+	if role != "admin" && role != "member" {
 		role = "member"
 	}
 	cleanEmail := strings.ToLower(strings.TrimSpace(email))
@@ -674,20 +679,13 @@ func (s *Store) GetDiscoverableUsers(viewerID string) ([]domain.User, error) {
 		mode = sys.SharingMode
 	}
 
-	if viewer.Role == "admin" || viewer.Role == "team_admin" || mode == "open" {
+	if viewer.Role == "admin" || mode == "open" || mode == "teams_only" {
 		return s.GetAllUsers()
 	}
 	if mode == "strict_private" {
 		return []domain.User{*viewer}, nil
 	}
 
-	// teams_only: if no teams exist yet, allow discovering users on this instance
-	var teamCount int
-	_ = s.db.QueryRow(`SELECT COUNT(*) FROM teams`).Scan(&teamCount)
-	if teamCount == 0 {
-		return s.GetAllUsers()
-	}
-
 	// users sharing at least one team, organization or space with viewer
 	rows, err := s.db.Query(
 		`SELECT DISTINCT `+userSelectCols+` FROM users WHERE id = ? OR id IN (
@@ -742,7 +740,7 @@ func (s *Store) UpdateUserFull(
 	if email != nil {
 		u.Email = strings.ToLower(strings.TrimSpace(*email))
 	}
-	if role != nil && (*role == "admin" || *role == "team_admin" || *role == "member") {
+	if role != nil && (*role == "admin" || *role == "member") {
 		u.Role = *role
 	}
 	if isActive != nil {
@@ -3313,7 +3311,7 @@ func (s *Store) GetOrganizationsForUser(userID string) ([]domain.Organization, e
 	var rows *sql.Rows
 	var err error
 
-	if viewer != nil && (viewer.Role == "admin" || viewer.Role == "team_admin") {
+	if viewer != nil && viewer.Role == "admin" {
 		rows, err = s.db.Query(
 			`SELECT id, name, owner_id, created_at FROM organizations ORDER BY created_at ASC`,
 		)
@@ -3474,11 +3472,10 @@ func (s *Store) GetTeamsForUser(userID string) ([]domain.Team, error) {
 	rows, err := s.db.Query(
 		`SELECT DISTINCT t.id, t.org_id, t.name, t.description, t.created_at
 		 FROM teams t
-		 LEFT JOIN team_members tm ON tm.team_id = t.id
+		 JOIN team_members tm ON tm.team_id = t.id
-		 LEFT JOIN organizations o ON o.id = t.org_id
+		 WHERE tm.user_id = ?
-		 WHERE tm.user_id = ? OR o.owner_id = ?
 		 ORDER BY t.created_at ASC`,
-		userID, userID,
+		userID,
 	)
 	if err != nil {
 		return []domain.Team{}, err
@@ -3501,8 +3498,39 @@ func (s *Store) GetTeamsForUser(userID string) ([]domain.Team, error) {
 	return teams, nil
 }
 
+func (s *Store) UpdateTeam(teamID, name, description string) (*domain.Team, error) {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return nil, errors.New("Name für die Gruppe ist erforderlich")
+	}
+	_, err := s.db.Exec(`UPDATE teams SET name = ?, description = ? WHERE id = ?`, name, strings.TrimSpace(description), teamID)
+	if err != nil {
+		return nil, err
+	}
+	return s.GetTeamByID(teamID)
+}
+
+func (s *Store) GetTeamMemberRole(teamID, userID string) (string, error) {
+	var role string
+	err := s.db.QueryRow(`SELECT role FROM team_members WHERE team_id = ? AND user_id = ?`, teamID, userID).Scan(&role)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return "", nil
+		}
+		return "", err
+	}
+	return role, nil
+}
+
+func (s *Store) CountTeamAdmins(teamID string) (int, error) {
+	var count int
+	err := s.db.QueryRow(`SELECT COUNT(*) FROM team_members WHERE team_id = ? AND role = 'admin'`, teamID).Scan(&count)
+	return count, err
+}
+
 func (s *Store) AddTeamMember(teamID, userID, role string) error {
-	if role == "" {
+	role = strings.ToLower(strings.TrimSpace(role))
+	if role != "admin" && role != "member" {
 		role = "member"
 	}
 	_, err := s.db.Exec(
@@ -3513,8 +3541,46 @@ func (s *Store) AddTeamMember(teamID, userID, role string) error {
 	return err
 }
 
+func (s *Store) UpdateTeamMemberRole(teamID, userID, role string) error {
+	role = strings.ToLower(strings.TrimSpace(role))
+	if role != "admin" && role != "member" {
+		return errors.New("Ungültige Rolle (erlaubt sind: admin, member)")
+	}
+	currentRole, err := s.GetTeamMemberRole(teamID, userID)
+	if err != nil {
+		return err
+	}
+	if currentRole == "" {
+		return errors.New("Benutzer ist kein Mitglied dieser Gruppe")
+	}
+	if currentRole == "admin" && role != "admin" {
+		adminCount, err := s.CountTeamAdmins(teamID)
+		if err != nil {
+			return err
+		}
+		if adminCount <= 1 {
+			return errors.New("Die Gruppe muss mindestens einen Gruppen-Admin behalten")
+		}
+	}
+	_, err = s.db.Exec(`UPDATE team_members SET role = ? WHERE team_id = ? AND user_id = ?`, role, teamID, userID)
+	return err
+}
+
 func (s *Store) RemoveTeamMember(teamID, userID string) error {
-	_, err := s.db.Exec(`DELETE FROM team_members WHERE team_id = ? AND user_id = ?`, teamID, userID)
+	currentRole, err := s.GetTeamMemberRole(teamID, userID)
+	if err != nil {
+		return err
+	}
+	if currentRole == "admin" {
+		adminCount, err := s.CountTeamAdmins(teamID)
+		if err != nil {
+			return err
+		}
+		if adminCount <= 1 {
+			return errors.New("Du bist der letzte Gruppen-Admin. Bitte ernenne zuerst einen anderen Admin oder lösche die Gruppe.")
+		}
+	}
+	_, err = s.db.Exec(`DELETE FROM team_members WHERE team_id = ? AND user_id = ?`, teamID, userID)
 	return err
 }
 
@@ -3545,7 +3611,7 @@ func (s *Store) GetTeamMembers(teamID string) ([]domain.TeamMember, error) {
 // --- USER INVITES ---
 
 func (s *Store) CreateUserInvite(createdBy, email, role, teamID string, validDays int) (*domain.UserInvite, error) {
-	if role != "admin" && role != "team_admin" && role != "member" {
+	if role != "admin" && role != "member" {
 		role = "member"
 	}
 	if validDays <= 0 || validDays > 365 {