feat: add recurring event deletion with three modes

Implement three deletion modes for recurring events:
- single: exclude specific occurrence via EXDATE mechanism
- future: set RRULE UNTIL to stop future occurrences
- all: delete entire event series

Changes include:
- Add exceptionDates field to CalendarEvent model
- Add RecurringDeleteMode type and DeleteRecurringEventDTO
- EventService.deleteRecurring() with mode-based logic using rrule library
- EventController DELETE endpoint accepts mode/occurrenceDate query params
- recurrenceExpander filters out exception dates during expansion
- AI tools support deleteMode and occurrenceDate for proposed deletions
- ChatService.confirmEvent() handles recurring delete modes
- New DeleteEventModal component for unified delete confirmation UI
- Calendar screen integrates modal for both recurring and non-recurring events

apps/server/src/services/ChatService.ts

@@ -10,11 +10,16 @@ import {
   UpdateEventDTO,
   EventAction,
   CreateMessageDTO,
+  RecurringDeleteMode,
 } from "@calchat/shared";
 import { ChatRepository, EventRepository, AIProvider } from "./interfaces";
+import { EventService } from "./EventService";
 import { getWeeksOverview, getMonthOverview } from "../utils/eventFormatters";
 
-type TestResponse = { content: string; proposedChanges?: ProposedEventChange[] };
+type TestResponse = {
+  content: string;
+  proposedChanges?: ProposedEventChange[];
+};
 
 // Test response index (cycles through responses)
 let responseIndex = 0;
@@ -25,8 +30,7 @@ const staticResponses: TestResponse[] = [
   // === MULTI-EVENT TEST RESPONSES ===
   // Response 0: 3 Meetings an verschiedenen Tagen
   {
-    content:
-      "Alles klar! Ich erstelle dir 3 Team-Meetings für diese Woche:",
+    content: "Alles klar! Ich erstelle dir 3 Team-Meetings für diese Woche:",
     proposedChanges: [
       {
         id: "multi-1-a",
@@ -62,8 +66,7 @@ const staticResponses: TestResponse[] = [
   },
   // Response 1: 5 Termine für einen Projekttag
   {
-    content:
-      "Ich habe deinen kompletten Projekttag am Dienstag geplant:",
+    content: "Ich habe deinen kompletten Projekttag am Dienstag geplant:",
     proposedChanges: [
       {
         id: "multi-2-a",
@@ -119,8 +122,7 @@ const staticResponses: TestResponse[] = [
   },
   // Response 2: 2 wiederkehrende Termine
   {
-    content:
-      "Ich erstelle dir zwei wiederkehrende Fitness-Termine:",
+    content: "Ich erstelle dir zwei wiederkehrende Fitness-Termine:",
     proposedChanges: [
       {
         id: "multi-3-a",
@@ -209,7 +211,8 @@ const staticResponses: TestResponse[] = [
           title: "Arzttermin Dr. Müller",
           startTime: getDay("Wednesday", 1, 9, 30),
           endTime: getDay("Wednesday", 1, 10, 30),
-          description: "Routineuntersuchung - Versichertenkarte nicht vergessen",
+          description:
+            "Routineuntersuchung - Versichertenkarte nicht vergessen",
         },
       },
     ],
@@ -403,6 +406,7 @@ export class ChatService {
   constructor(
     private chatRepo: ChatRepository,
     private eventRepo: EventRepository,
+    private eventService: EventService,
     private aiProvider: AIProvider,
   ) {}
 
@@ -462,9 +466,15 @@ export class ChatService {
     event?: CreateEventDTO,
     eventId?: string,
     updates?: UpdateEventDTO,
+    deleteMode?: RecurringDeleteMode,
+    occurrenceDate?: string,
   ): Promise<ChatResponse> {
     // Update specific proposal with respondedAction
-    await this.chatRepo.updateProposalResponse(messageId, proposalId, "confirm");
+    await this.chatRepo.updateProposalResponse(
+      messageId,
+      proposalId,
+      "confirm",
+    );
 
     // Perform the actual event operation
     let content: string;
@@ -478,10 +488,25 @@ export class ChatService {
         ? `Der Termin "${updatedEvent.title}" wurde aktualisiert.`
         : "Termin nicht gefunden.";
     } else if (action === "delete" && eventId) {
-      await this.eventRepo.delete(eventId);
+      // Use deleteRecurring for proper handling of recurring events
+      const mode = deleteMode || "all";
+      await this.eventService.deleteRecurring(
+        eventId,
+        userId,
+        mode,
+        occurrenceDate,
+      );
+
+      // Build appropriate response message
+      let deleteDescription = "";
+      if (deleteMode === "single") {
+        deleteDescription = " (dieses Vorkommen)";
+      } else if (deleteMode === "future") {
+        deleteDescription = " (dieses und zukünftige Vorkommen)";
+      }
       content = event?.title
-        ? `Der Termin "${event.title}" wurde gelöscht.`
-        : "Der Termin wurde gelöscht.";
+        ? `Der Termin "${event.title}"${deleteDescription} wurde gelöscht.`
+        : `Der Termin${deleteDescription} wurde gelöscht.`;
     } else {
       content = "Ungültige Aktion.";
     }