fix: Retry sends message with retry flag to avoid duplicate storage

Added retry:true flag to sendChatMessage input. Server skips storing
the user message when retry is set. Frontend uses a dedicated
retryLastMessage function that skips the optimistic message add.

apps/server/trpc/routers/chat-session.ts

@@ -26,6 +26,7 @@ export function chatSessionProcedures(publicProcedure: ProcedureBuilder) {
         targetId: z.string().min(1),
         initiativeId: z.string().min(1),
         message: z.string().min(1),
+        retry: z.boolean().optional(),
         provider: z.string().optional(),
       }))
       .mutation(async ({ ctx, input }) => {
@@ -49,18 +50,20 @@ export function chatSessionProcedures(publicProcedure: ProcedureBuilder) {
           });
         }
 
-        // Store user message
-        await chatRepo.createMessage({
-          chatSessionId: session.id,
-          role: 'user',
-          content: input.message,
-        });
+        // Store user message (skip on retry — message already exists)
+        if (!input.retry) {
+          await chatRepo.createMessage({
+            chatSessionId: session.id,
+            role: 'user',
+            content: input.message,
+          });
 
-        ctx.eventBus.emit({
-          type: 'chat:message_created' as const,
-          timestamp: new Date(),
-          payload: { chatSessionId: session.id, role: 'user' as const },
-        });
+          ctx.eventBus.emit({
+            type: 'chat:message_created' as const,
+            timestamp: new Date(),
+            payload: { chatSessionId: session.id, role: 'user' as const },
+          });
+        }
 
         // Check if agent exists and is waiting for input
         if (session.agentId) {

apps/web/src/components/chat/ChatSlideOver.tsx

@@ -42,7 +42,7 @@ function ChatSlideOverInner({
   initiativeId: string;
   onClose: () => void;
 }) {
-  const { messages, agentStatus, agentError, sendMessage, closeSession, isSending } =
+  const { messages, agentStatus, agentError, sendMessage, retryLastMessage, closeSession, isSending } =
     useChatSession(target.type, target.id, initiativeId);
 
   const scrollRef = useRef<HTMLDivElement>(null);
@@ -145,11 +145,7 @@ function ChatSlideOverInner({
                   variant="outline"
                   size="sm"
                   className="h-6 gap-1.5 text-xs"
-                  onClick={() => {
-                    // Re-send the last user message to retry
-                    const lastUserMsg = [...messages].reverse().find(m => m.role === 'user');
-                    if (lastUserMsg) sendMessage(lastUserMsg.content);
-                  }}
+                  onClick={retryLastMessage}
                 >
                   <RotateCcw className="h-3 w-3" />
                   Retry

apps/web/src/hooks/useChatSession.ts

@@ -30,6 +30,7 @@ export interface UseChatSessionResult {
   agentStatus: ChatAgentStatus;
   agentError: string | null;
   sendMessage: (message: string) => void;
+  retryLastMessage: () => void;
   closeSession: () => void;
   isSending: boolean;
   isLoading: boolean;
@@ -163,6 +164,21 @@ export function useChatSession(
     [targetType, targetId, initiativeId],
   );
 
+  const messagesRef = useRef(messages);
+  messagesRef.current = messages;
+
+  const retryLastMessage = useCallback(() => {
+    const lastUserMsg = [...messagesRef.current].reverse().find(m => m.role === 'user');
+    if (!lastUserMsg) return;
+    sendMutateRef.current({
+      targetType,
+      targetId,
+      initiativeId,
+      message: lastUserMsg.content,
+      retry: true,
+    });
+  }, [targetType, targetId, initiativeId]);
+
   const closeSession = useCallback(() => {
     const s = sessionRef.current;
     if (s) {
@@ -179,6 +195,7 @@ export function useChatSession(
     agentStatus,
     agentError,
     sendMessage,
+    retryLastMessage,
     closeSession,
     isSending,
     isLoading,