feat: support multiple event proposals in single AI response

- Change proposedChange to proposedChanges array in ChatMessage type
- Add unique id and individual respondedAction to each ProposedEventChange
- Implement arrow navigation UI for multiple proposals with "Event X von Y" counter
- Add updateProposalResponse() method for per-proposal confirm/reject tracking
- GPTAdapter now collects multiple tool call results into proposals array
- Add RRULE documentation to system prompt (separate events for different times)
- Fix RRULE parsing to strip RRULE: prefix if present
- Add log summarization for large args (conversationHistory, existingEvents)
- Keep proposedChanges logged in full for debugging AI issues

apps/client/src/stores/ChatStore.ts

@@ -7,8 +7,7 @@ export type MessageData = {
   id: string;
   side: BubbleSide;
   content: string;
-  proposedChange?: ProposedEventChange;
-  respondedAction?: "confirm" | "reject";
+  proposedChanges?: ProposedEventChange[];
   conversationId?: string;
 };
 
@@ -46,8 +45,7 @@ export function chatMessageToMessageData(msg: ChatMessage): MessageData {
     id: msg.id,
     side: msg.sender === "assistant" ? "left" : "right",
     content: msg.content,
-    proposedChange: msg.proposedChange,
-    respondedAction: msg.respondedAction,
+    proposedChanges: msg.proposedChanges,
     conversationId: msg.conversationId,
   };
 }