feat(calendar): implement local calendar invitations with email notifications

- Added functionality to create, accept, decline, and delete local calendar invitations.
- Integrated email notifications for calendar event invitations and deletions.
- Updated database schema to support local invitations and outbound event tracking.
- Enhanced the calendar UI to display pending invitations and allow users to manage them.
- Localized new strings for invitations in English and German.

src/i18n/de.json

@@ -411,6 +411,8 @@
     "roomDeletedNotice": "Dieser Raum wurde vom Besitzer auf der Ursprungsinstanz gelöscht und ist nicht mehr verfügbar.",
     "calendarEvent": "Kalendereinladung",
     "calendarAccepted": "Kalender-Event angenommen und in deinen Kalender eingetragen!",
+    "localCalendarEvent": "Lokale Kalendereinladung",
+    "calendarLocalAccepted": "Einladung angenommen – Event wurde in deinen Kalender eingetragen!",
     "invitationRemoved": "Einladung entfernt",
     "removeInvitation": "Einladung entfernen"
   },
@@ -458,6 +460,11 @@
     "shareAdded": "Benutzer zum Event hinzugefügt",
     "shareRemoved": "Freigabe entfernt",
     "shareFailed": "Event konnte nicht geteilt werden",
+    "invitationSent": "Einladung gesendet!",
+    "invitationCancelled": "Einladung widerrufen",
+    "invitationPending": "Einladung ausstehend",
+    "pendingInvitations": "Ausstehende Einladungen",
+    "accepted": "Angenommen",
     "sendFederated": "An Remote senden",
     "sendFederatedTitle": "Event an Remote-Instanz senden",
     "sendFederatedDesc": "Sende dieses Kalender-Event an einen Benutzer auf einer anderen Redlight-Instanz. Der Empfänger muss die Einladung zuerst annehmen, bevor das Event in seinem Kalender erscheint.",

src/i18n/en.json

@@ -411,6 +411,8 @@
     "roomDeletedNotice": "This room has been deleted by the owner on the origin instance and is no longer available.",
     "calendarEvent": "Calendar Invitation",
     "calendarAccepted": "Calendar event accepted and added to your calendar!",
+    "localCalendarEvent": "Local Calendar Invitation",
+    "calendarLocalAccepted": "Invitation accepted – event added to your calendar!",
     "invitationRemoved": "Invitation removed",
     "removeInvitation": "Remove invitation"
   },
@@ -458,6 +460,11 @@
     "shareAdded": "User added to event",
     "shareRemoved": "Share removed",
     "shareFailed": "Could not share event",
+    "invitationSent": "Invitation sent!",
+    "invitationCancelled": "Invitation cancelled",
+    "invitationPending": "Invitation pending",
+    "pendingInvitations": "Pending Invitations",
+    "accepted": "Accepted",
     "sendFederated": "Send to remote",
     "sendFederatedTitle": "Send Event to Remote Instance",
     "sendFederatedDesc": "Send this calendar event to a user on another Redlight instance. The recipient must accept the invitation before the event appears in their calendar.",

src/pages/Calendar.jsx

@@ -39,6 +39,7 @@ export default function Calendar() {
   const [shareSearch, setShareSearch] = useState('');
   const [shareResults, setShareResults] = useState([]);
   const [sharedUsers, setSharedUsers] = useState([]);
+  const [pendingInvitations, setPendingInvitations] = useState([]);
   const [fedAddress, setFedAddress] = useState('');
   const [fedSending, setFedSending] = useState(false);
 
@@ -269,9 +270,11 @@ export default function Calendar() {
     setShowShare(ev);
     setShareSearch('');
     setShareResults([]);
+    setPendingInvitations([]);
     try {
       const res = await api.get(`/calendar/events/${ev.id}`);
       setSharedUsers(res.data.sharedUsers || []);
+      setPendingInvitations(res.data.pendingInvitations || []);
     } catch { /* ignore */ }
   };
 
@@ -281,7 +284,8 @@ export default function Calendar() {
     try {
       const res = await api.get(`/rooms/users/search?q=${encodeURIComponent(query)}`);
       const sharedIds = new Set(sharedUsers.map(u => u.id));
-      setShareResults(res.data.users.filter(u => !sharedIds.has(u.id)));
+      const pendingIds = new Set(pendingInvitations.map(u => u.user_id));
+      setShareResults(res.data.users.filter(u => !sharedIds.has(u.id) && !pendingIds.has(u.id)));
     } catch { setShareResults([]); }
   };
 
@@ -290,9 +294,10 @@ export default function Calendar() {
     try {
       const res = await api.post(`/calendar/events/${showShare.id}/share`, { user_id: userId });
       setSharedUsers(res.data.sharedUsers);
+      setPendingInvitations(res.data.pendingInvitations || []);
       setShareSearch('');
       setShareResults([]);
-      toast.success(t('calendar.shareAdded'));
+      toast.success(t('calendar.invitationSent'));
     } catch (err) {
       toast.error(err.response?.data?.error || t('calendar.shareFailed'));
     }
@@ -303,10 +308,21 @@ export default function Calendar() {
     try {
       const res = await api.delete(`/calendar/events/${showShare.id}/share/${userId}`);
       setSharedUsers(res.data.sharedUsers);
+      setPendingInvitations(res.data.pendingInvitations || []);
       toast.success(t('calendar.shareRemoved'));
     } catch { toast.error(t('calendar.shareFailed')); }
   };
 
+  const handleCancelInvitation = async (userId) => {
+    if (!showShare) return;
+    try {
+      const res = await api.delete(`/calendar/events/${showShare.id}/share/${userId}`);
+      setSharedUsers(res.data.sharedUsers);
+      setPendingInvitations(res.data.pendingInvitations || []);
+      toast.success(t('calendar.invitationCancelled'));
+    } catch { toast.error(t('calendar.shareFailed')); }
+  };
+
   const handleFedSend = async (e) => {
     e.preventDefault();
     if (!showFedShare) return;
@@ -721,8 +737,36 @@ export default function Calendar() {
               )}
             </div>
 
+            {pendingInvitations.length > 0 && (
+              <div className="space-y-2">
+                <p className="text-xs font-semibold text-th-text-s uppercase tracking-wider">{t('calendar.pendingInvitations')}</p>
+                {pendingInvitations.map(u => (
+                  <div key={u.user_id} className="flex items-center justify-between gap-3 p-3 bg-th-bg-s rounded-lg border border-th-border border-dashed">
+                    <div className="flex items-center gap-3 min-w-0">
+                      <div
+                        className="w-8 h-8 rounded-full flex items-center justify-center text-white text-xs font-bold flex-shrink-0"
+                        style={{ backgroundColor: u.avatar_color || '#6366f1' }}
+                      >
+                        {(u.display_name || u.name).split(' ').map(n => n[0]).join('').toUpperCase().slice(0, 2)}
+                      </div>
+                      <div className="min-w-0">
+                        <div className="text-sm font-medium text-th-text truncate">{u.display_name || u.name}</div>
+                        <div className="text-xs text-th-warning">{t('calendar.invitationPending')}</div>
+                      </div>
+                    </div>
+                    <button onClick={() => handleCancelInvitation(u.user_id)} className="p-1.5 rounded-lg hover:bg-th-hover text-th-text-s hover:text-th-error transition-colors">
+                      <X size={16} />
+                    </button>
+                  </div>
+                ))}
+              </div>
+            )}
+
             {sharedUsers.length > 0 && (
               <div className="space-y-2">
+                {pendingInvitations.length > 0 && (
+                  <p className="text-xs font-semibold text-th-text-s uppercase tracking-wider">{t('calendar.accepted')}</p>
+                )}
                 {sharedUsers.map(u => (
                   <div key={u.id} className="flex items-center justify-between gap-3 p-3 bg-th-bg-s rounded-lg border border-th-border">
                     <div className="flex items-center gap-3 min-w-0">

src/pages/FederationInbox.jsx

@@ -8,16 +8,19 @@ export default function FederationInbox() {
     const { t } = useLanguage();
     const [invitations, setInvitations] = useState([]);
     const [calendarInvitations, setCalendarInvitations] = useState([]);
+    const [localCalInvitations, setLocalCalInvitations] = useState([]);
     const [loading, setLoading] = useState(true);
 
     const fetchInvitations = async () => {
         try {
-            const [roomRes, calRes] = await Promise.all([
+            const [roomRes, calRes, localCalRes] = await Promise.all([
                 api.get('/federation/invitations'),
                 api.get('/federation/calendar-invitations').catch(() => ({ data: { invitations: [] } })),
+                api.get('/calendar/local-invitations').catch(() => ({ data: { invitations: [] } })),
             ]);
             setInvitations(roomRes.data.invitations || []);
             setCalendarInvitations(calRes.data.invitations || []);
+            setLocalCalInvitations(localCalRes.data.invitations || []);
         } catch {
             toast.error(t('federation.loadFailed'));
         } finally {
@@ -91,6 +94,37 @@ export default function FederationInbox() {
         }
     };
 
+    // ── Local calendar invitation actions ───────────────────────────────────
+    const handleLocalCalAccept = async (id) => {
+        try {
+            await api.post(`/calendar/local-invitations/${id}/accept`);
+            toast.success(t('federation.calendarLocalAccepted'));
+            fetchInvitations();
+        } catch {
+            toast.error(t('federation.acceptFailed'));
+        }
+    };
+
+    const handleLocalCalDecline = async (id) => {
+        try {
+            await api.delete(`/calendar/local-invitations/${id}`);
+            toast.success(t('federation.declined'));
+            fetchInvitations();
+        } catch {
+            toast.error(t('federation.declineFailed'));
+        }
+    };
+
+    const handleLocalCalDelete = async (id) => {
+        try {
+            await api.delete(`/calendar/local-invitations/${id}`);
+            toast.success(t('federation.invitationRemoved'));
+            fetchInvitations();
+        } catch {
+            toast.error(t('federation.declineFailed'));
+        }
+    };
+
     if (loading) {
         return (
             <div className="flex items-center justify-center py-20">
@@ -103,9 +137,11 @@ export default function FederationInbox() {
     const pastRooms = invitations.filter(i => i.status !== 'pending');
     const pendingCal = calendarInvitations.filter(i => i.status === 'pending');
     const pastCal = calendarInvitations.filter(i => i.status !== 'pending');
+    const pendingLocalCal = localCalInvitations.filter(i => i.status === 'pending');
+    const pastLocalCal = localCalInvitations.filter(i => i.status !== 'pending');
 
-    const totalPending = pendingRooms.length + pendingCal.length;
-    const totalPast = pastRooms.length + pastCal.length;
+    const totalPending = pendingRooms.length + pendingCal.length + pendingLocalCal.length;
+    const totalPast = pastRooms.length + pastCal.length + pastLocalCal.length;
 
     return (
         <div>
@@ -196,6 +232,45 @@ export default function FederationInbox() {
                                 </div>
                             </div>
                         ))}
+
+                        {/* Pending local calendar invitations */}
+                        {pendingLocalCal.map(inv => (
+                            <div key={`localcal-${inv.id}`} className="card p-5 border-l-4 border-l-th-accent">
+                                <div className="flex flex-col sm:flex-row sm:items-center justify-between gap-4">
+                                    <div className="min-w-0">
+                                        <div className="flex items-center gap-2 mb-1">
+                                            <Calendar size={16} className="text-th-accent flex-shrink-0" />
+                                            <span className="text-xs font-semibold uppercase tracking-wide text-th-accent mr-1">
+                                                {t('federation.localCalendarEvent')}
+                                            </span>
+                                            <h3 className="text-base font-semibold text-th-text truncate">{inv.title}</h3>
+                                        </div>
+                                        <p className="text-sm text-th-text-s">
+                                            {t('federation.from')}: <span className="font-medium text-th-text">{inv.from_name}</span>
+                                        </p>
+                                        <p className="text-sm text-th-text-s mt-1">
+                                            {new Date(inv.start_time).toLocaleString()} – {new Date(inv.end_time).toLocaleString()}
+                                        </p>
+                                        {inv.description && (
+                                            <p className="text-sm text-th-text-s mt-1 italic">"{inv.description}"</p>
+                                        )}
+                                        <p className="text-xs text-th-text-s mt-1">
+                                            {new Date(inv.created_at).toLocaleString()}
+                                        </p>
+                                    </div>
+                                    <div className="flex items-center gap-2 flex-shrink-0">
+                                        <button onClick={() => handleLocalCalAccept(inv.id)} className="btn-primary text-sm">
+                                            <Check size={16} />
+                                            {t('federation.accept')}
+                                        </button>
+                                        <button onClick={() => handleLocalCalDecline(inv.id)} className="btn-secondary text-sm">
+                                            <X size={16} />
+                                            {t('federation.decline')}
+                                        </button>
+                                    </div>
+                                </div>
+                            </div>
+                        ))}
                     </div>
                 </div>
             )}
@@ -284,6 +359,36 @@ export default function FederationInbox() {
                                 </div>
                             </div>
                         ))}
+
+                        {/* Past local calendar invitations */}
+                        {pastLocalCal.map(inv => (
+                            <div key={`localcal-past-${inv.id}`} className="card p-4 opacity-70">
+                                <div className="flex items-center justify-between gap-4">
+                                    <div className="min-w-0 flex items-center gap-2">
+                                        <Calendar size={14} className="text-th-text-s flex-shrink-0" />
+                                        <div className="min-w-0">
+                                            <h3 className="text-sm font-medium text-th-text truncate">{inv.title}</h3>
+                                            <p className="text-xs text-th-text-s">{inv.from_name} · {new Date(inv.start_time).toLocaleDateString()}</p>
+                                        </div>
+                                    </div>
+                                    <div className="flex items-center gap-2 flex-shrink-0">
+                                        <span className={`text-xs font-medium px-2 py-1 rounded-full ${inv.status === 'accepted'
+                                            ? 'bg-th-success/15 text-th-success'
+                                            : 'bg-th-error/15 text-th-error'
+                                        }`}>
+                                            {inv.status === 'accepted' ? t('federation.statusAccepted') : t('federation.statusDeclined')}
+                                        </span>
+                                        <button
+                                            onClick={() => handleLocalCalDelete(inv.id)}
+                                            className="btn-ghost text-xs py-1.5 px-2 text-th-text-s hover:text-th-error"
+                                            title={t('federation.removeInvitation')}
+                                        >
+                                            <Trash2 size={14} />
+                                        </button>
+                                    </div>
+                                </div>
+                            </div>
+                        ))}
                     </div>
                 </div>
             )}