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/client/src/app/(tabs)/chat.tsx

@@ -20,7 +20,7 @@ import {
   chatMessageToMessageData,
   MessageData,
 } from "../../stores";
-import { ProposedEventChange } from "@calchat/shared";
+import { ProposedEventChange, RespondedAction } from "@calchat/shared";
 import { ProposedEventCard } from "../../components/ProposedEventCard";
 import { Ionicons } from "@expo/vector-icons";
 import TypingIndicator from "../../components/TypingIndicator";
@@ -104,7 +104,7 @@ const Chat = () => {
   };
 
   const handleEventResponse = async (
-    action: "confirm" | "reject",
+    action: RespondedAction,
     messageId: string,
     conversationId: string,
     proposalId: string,
@@ -114,7 +114,9 @@ const Chat = () => {
     const message = messages.find((m) => m.id === messageId);
     if (message?.proposedChanges) {
       const updatedProposals = message.proposedChanges.map((p) =>
-        p.id === proposalId ? { ...p, respondedAction: action as "confirm" | "reject" } : p,
+        p.id === proposalId
+          ? { ...p, respondedAction: action }
+          : p,
       );
       updateMessage(messageId, { proposedChanges: updatedProposals });
     }
@@ -130,8 +132,14 @@ const Chat = () => {
               proposedChange.event,
               proposedChange.eventId,
               proposedChange.updates,
+              proposedChange.deleteMode,
+              proposedChange.occurrenceDate,
             )
-          : await ChatService.rejectEvent(conversationId, messageId, proposalId);
+          : await ChatService.rejectEvent(
+              conversationId,
+              messageId,
+              proposalId,
+            );
 
       const botMessage: MessageData = {
         id: response.message.id,
@@ -225,14 +233,21 @@ const Chat = () => {
                 )
               }
               onReject={(proposalId) =>
-                handleEventResponse("reject", item.id, item.conversationId!, proposalId)
+                handleEventResponse(
+                  "reject",
+                  item.id,
+                  item.conversationId!,
+                  proposalId,
+                )
               }
             />
           )}
           keyExtractor={(item) => item.id}
           keyboardDismissMode="interactive"
           keyboardShouldPersistTaps="handled"
-          ListFooterComponent={isWaitingForResponse ? <TypingIndicator /> : null}
+          ListFooterComponent={
+            isWaitingForResponse ? <TypingIndicator /> : null
+          }
         />
         <ChatInput onSend={handleSend} />
       </KeyboardAvoidingView>
@@ -251,7 +266,9 @@ const ChatHeader = () => {
           borderColor: theme.primeFg,
         }}
       ></View>
-      <Text className="text-lg pl-3" style={{ color: theme.textPrimary }}>CalChat</Text>
+      <Text className="text-lg pl-3" style={{ color: theme.textPrimary }}>
+        CalChat
+      </Text>
       <View
         className="h-2 bg-black"
         style={{
@@ -329,9 +346,7 @@ const ChatMessage = ({
 
   const goToPrev = () => setCurrentIndex((i) => Math.max(0, i - 1));
   const goToNext = () =>
-    setCurrentIndex((i) =>
-      Math.min((proposedChanges?.length || 1) - 1, i + 1),
-    );
+    setCurrentIndex((i) => Math.min((proposedChanges?.length || 1) - 1, i + 1));
 
   const canGoPrev = currentIndex > 0;
   const canGoNext = currentIndex < (proposedChanges?.length || 1) - 1;
@@ -344,7 +359,9 @@ const ChatMessage = ({
         minWidth: hasProposals ? "75%" : undefined,
       }}
     >
-      <Text className="p-2" style={{ color: theme.textPrimary }}>{content}</Text>
+      <Text className="p-2" style={{ color: theme.textPrimary }}>
+        {content}
+      </Text>
 
       {hasProposals && currentProposal && onConfirm && onReject && (
         <View>
@@ -358,11 +375,7 @@ const ChatMessage = ({
                 className="p-1"
                 style={{ opacity: canGoPrev ? 1 : 0.3 }}
               >
-                <Ionicons
-                  name="chevron-back"
-                  size={24}
-                  color={theme.primeFg}
-                />
+                <Ionicons name="chevron-back" size={24} color={theme.primeFg} />
               </Pressable>
             )}