fix: self-clear Quick Chat send-button tap latch on mobile

The send/stop buttons run their action on pointerdown/touchstart and set a
shared handledMobileActionRef latch so the trailing synthetic onClick does not
double-fire. The latch was only cleared inside onClick, but iOS suppresses that
click after preventDefault() in touchstart — leaving it stuck true, so the next
real click (e.g. after switching chats) was swallowed and the button looked
dead. Make the latch self-clearing (auto-reset timer + consume-on-click) so it
can never persist across taps; also stops a stuck stop-button latch from killing
the next send tap.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.changeset/fix-quick-chat-send-tap-latch.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix the Quick Chat send button going dead after switching chats on mobile. The send and stop buttons run their action on `pointerdown`/`touchstart` (iOS needs that) and set a shared `handledMobileActionRef` latch so the trailing synthetic `onClick` doesn't double-fire — but the latch was only ever cleared inside `onClick`. On iOS, `preventDefault()` in `touchstart` routinely suppresses that click, leaving the latch stuck `true`, so the next real click (e.g. after opening a different chat) was swallowed and the button appeared unresponsive. The latch is now self-clearing: it auto-resets on a short timer after each gesture and is consumed-and-cancelled when a click does fire, so it can never persist across taps. Because the ref is shared by both buttons, this also stops a stuck stop-button latch from killing the next send tap.

packages/dashboard/app/components/QuickChatFAB.tsx

@@ -1070,6 +1070,7 @@ export function QuickChatFAB({
   const pendingAttachmentsRef = useRef<PendingAttachment[]>([]);
   const shouldAutoFocusComposerRef = useRef(false);
   const handledMobileActionRef = useRef(false);
+  const handledMobileActionTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   const preserveComposerFocusRef = useRef(false);
   // Always-mounted offscreen input used to claim the iOS soft keyboard
   // synchronously inside the FAB click gesture, before the real composer
@@ -1972,6 +1973,43 @@ export function QuickChatFAB({
     preserveComposerFocusRef.current = true;
   }, []);
 
+  // Latch that a mobile pointer/touch handler already performed a button's
+  // action, so the synthetic onClick that trails the gesture is ignored
+  // (prevents a double send/stop). On iOS, preventDefault() in
+  // touchstart/pointerdown frequently suppresses that click entirely, so we
+  // also clear the latch on a timer: without it the ref stays stuck `true` and
+  // swallows the *next* real click (e.g. after switching chats), making the
+  // button look dead. The latch is shared by the send and stop buttons, so a
+  // stuck value cross-contaminates between them.
+  const markHandledMobileAction = useCallback(() => {
+    handledMobileActionRef.current = true;
+    if (handledMobileActionTimerRef.current != null) {
+      clearTimeout(handledMobileActionTimerRef.current);
+    }
+    handledMobileActionTimerRef.current = setTimeout(() => {
+      handledMobileActionRef.current = false;
+      handledMobileActionTimerRef.current = null;
+    }, 700);
+  }, []);
+
+  // If a mobile handler already ran this gesture's action, consume the latch
+  // (and cancel its timer) so the trailing onClick bails without double-firing.
+  const consumeHandledMobileAction = useCallback(() => {
+    if (!handledMobileActionRef.current) return false;
+    handledMobileActionRef.current = false;
+    if (handledMobileActionTimerRef.current != null) {
+      clearTimeout(handledMobileActionTimerRef.current);
+      handledMobileActionTimerRef.current = null;
+    }
+    return true;
+  }, []);
+
+  useEffect(() => () => {
+    if (handledMobileActionTimerRef.current != null) {
+      clearTimeout(handledMobileActionTimerRef.current);
+    }
+  }, []);
+
   const handleSendMessage = useCallback(async () => {
     const trimmed = messageInput.trim();
     const attachmentsToSend = pendingAttachmentsRef.current;
@@ -3048,14 +3086,14 @@ export function QuickChatFAB({
                       if (typeof window === "undefined" || window.innerWidth > QUICK_CHAT_DESKTOP_BREAKPOINT) return;
                       event.preventDefault();
                       if (event.pointerType && event.pointerType !== "mouse") {
-                        handledMobileActionRef.current = true;
+                        markHandledMobileAction();
                         stopStreaming();
                       }
                     }}
                     onTouchStart={(event) => {
                       if (typeof window === "undefined" || window.innerWidth > QUICK_CHAT_DESKTOP_BREAKPOINT) return;
                       event.preventDefault();
-                      handledMobileActionRef.current = true;
+                      markHandledMobileAction();
                       stopStreaming();
                     }}
                     onMouseDown={(event) => {
@@ -3063,10 +3101,7 @@ export function QuickChatFAB({
                       event.preventDefault();
                     }}
                     onClick={() => {
-                      if (handledMobileActionRef.current) {
+                      if (consumeHandledMobileAction()) return;
-                        handledMobileActionRef.current = false;
-                        return;
-                      }
                       stopStreaming();
                     }}
                     aria-label={t("chat.stopGeneration", "Stop generation")}
@@ -3082,7 +3117,7 @@ export function QuickChatFAB({
                       if (typeof window === "undefined" || window.innerWidth > QUICK_CHAT_DESKTOP_BREAKPOINT) return;
                       event.preventDefault();
                       if (event.pointerType && event.pointerType !== "mouse") {
-                        handledMobileActionRef.current = true;
+                        markHandledMobileAction();
                         markPreserveComposerFocus();
                         focusComposerInput();
                         void handleSendMessage();
@@ -3091,7 +3126,7 @@ export function QuickChatFAB({
                     onTouchStart={(event) => {
                       if (typeof window === "undefined" || window.innerWidth > QUICK_CHAT_DESKTOP_BREAKPOINT) return;
                       event.preventDefault();
-                      handledMobileActionRef.current = true;
+                      markHandledMobileAction();
                       markPreserveComposerFocus();
                       focusComposerInput();
                       void handleSendMessage();
@@ -3101,10 +3136,7 @@ export function QuickChatFAB({
                       event.preventDefault();
                     }}
                     onClick={() => {
-                      if (handledMobileActionRef.current) {
+                      if (consumeHandledMobileAction()) return;
-                        handledMobileActionRef.current = false;
-                        return;
-                      }
                       void handleSendMessage();
                     }}
                     disabled={sendDisabled}