fix: use patch for calendar slot agent updates

plugin/calendar/calendar-bridge.ts

@@ -107,7 +107,7 @@ export class CalendarBridgeClient {
    */
   async updateSlot(slotId: number, update: SlotAgentUpdate): Promise<boolean> {
     const url = `${this.baseUrl}/calendar/slots/${slotId}/agent-update`;
-    return this.postBoolean(url, update);
+    return this.sendBoolean('PATCH', url, update);
   }
 
   /**
@@ -166,7 +166,7 @@ export class CalendarBridgeClient {
       claw_identifier: this.config.clawIdentifier,
       ...params,
     };
-    return this.postBoolean(url, body);
+    return this.sendBoolean('POST', url, body);
   }
 
   // -------------------------------------------------------------------------
@@ -195,13 +195,13 @@ export class CalendarBridgeClient {
     }
   }
 
-  private async postBoolean(url: string, body: unknown): Promise<boolean> {
+  private async sendBoolean(method: 'POST' | 'PATCH', url: string, body: unknown): Promise<boolean> {
     const controller = new AbortController();
     const timeout = setTimeout(() => controller.abort(), this.timeoutMs);
 
     try {
       const response = await fetch(url, {
-        method: 'POST',
+        method,
         headers: {
           'Content-Type': 'application/json',
           'X-Agent-ID': this.config.agentId,