fix(core): add onSettled invalidation to all optimistic mutations + enable refetchOnReconnect

P0: Add onSettled: invalidateQueries to 10 mutations that had onMutate
optimistic updates but no server confirmation. With staleTime: Infinity,
missing onSettled means cache could permanently drift from server state.

Mutations fixed:
- useDeleteIssue, useBatchDeleteIssues (issue list)
- useUpdateComment, useDeleteComment, useToggleCommentReaction (timeline)
- useToggleIssueReaction (reactions)
- useToggleIssueSubscriber (subscribers)
- useMarkInboxRead, useArchiveInbox, useMarkAllInboxRead (inbox)

P2: Change refetchOnReconnect from false to true as safety net
for HTTP reconnection before WS reconnection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/core/inbox/mutations.ts

@@ -20,6 +20,9 @@ export function useMarkInboxRead() {
     onError: (_err, _id, ctx) => {
       if (ctx?.prev) qc.setQueryData(inboxKeys.list(wsId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: inboxKeys.list(wsId) });
+    },
   });
 }
 
@@ -46,6 +49,9 @@ export function useArchiveInbox() {
     onError: (_err, _id, ctx) => {
       if (ctx?.prev) qc.setQueryData(inboxKeys.list(wsId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: inboxKeys.list(wsId) });
+    },
   });
 }
 
@@ -67,6 +73,9 @@ export function useMarkAllInboxRead() {
     onError: (_err, _vars, ctx) => {
       if (ctx?.prev) qc.setQueryData(inboxKeys.list(wsId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: inboxKeys.list(wsId) });
+    },
   });
 }
 

apps/web/core/issues/mutations.ts

@@ -35,8 +35,14 @@ export function useUpdateIssue() {
   return useMutation({
     mutationFn: ({ id, ...data }: { id: string } & UpdateIssueRequest) =>
       api.updateIssue(id, data),
-    onMutate: async ({ id, ...data }) => {
-      await qc.cancelQueries({ queryKey: issueKeys.list(wsId) });
+    onMutate: ({ id, ...data }) => {
+      // Fire-and-forget: don't await — keeps onMutate synchronous so the
+      // cache update happens in the same tick as mutate(). Awaiting would
+      // yield to the event loop, letting @dnd-kit reset its visual state
+      // before the optimistic update lands → card flickers back briefly.
+      // Safe because staleTime: Infinity means no background refetch is
+      // in-flight during normal operation.
+      qc.cancelQueries({ queryKey: issueKeys.list(wsId) });
       const prevList = qc.getQueryData<ListIssuesResponse>(issueKeys.list(wsId));
       const prevDetail = qc.getQueryData<Issue>(issueKeys.detail(wsId, id));
 
@@ -89,6 +95,9 @@ export function useDeleteIssue() {
     onError: (_err, _id, ctx) => {
       if (ctx?.prevList) qc.setQueryData(issueKeys.list(wsId), ctx.prevList);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.list(wsId) });
+    },
   });
 }
 
@@ -149,6 +158,9 @@ export function useBatchDeleteIssues() {
     onError: (_err, _ids, ctx) => {
       if (ctx?.prevList) qc.setQueryData(issueKeys.list(wsId), ctx.prevList);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.list(wsId) });
+    },
   });
 }
 
@@ -215,6 +227,9 @@ export function useUpdateComment(issueId: string) {
       if (ctx?.prev)
         qc.setQueryData(issueKeys.timeline(issueId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.timeline(issueId) });
+    },
   });
 }
 
@@ -251,6 +266,9 @@ export function useDeleteComment(issueId: string) {
       if (ctx?.prev)
         qc.setQueryData(issueKeys.timeline(issueId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.timeline(issueId) });
+    },
   });
 }
 
@@ -339,6 +357,9 @@ export function useToggleCommentReaction(issueId: string) {
       if (ctx?.prev)
         qc.setQueryData(issueKeys.timeline(issueId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.timeline(issueId) });
+    },
   });
 }
 
@@ -404,6 +425,9 @@ export function useToggleIssueReaction(issueId: string) {
       if (ctx?.prev)
         qc.setQueryData(issueKeys.reactions(issueId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.reactions(issueId) });
+    },
   });
 }
 
@@ -470,5 +494,8 @@ export function useToggleIssueSubscriber(issueId: string) {
       if (ctx?.prev)
         qc.setQueryData(issueKeys.subscribers(issueId), ctx.prev);
     },
+    onSettled: () => {
+      qc.invalidateQueries({ queryKey: issueKeys.subscribers(issueId) });
+    },
   });
 }

apps/web/core/query-client.ts

@@ -7,7 +7,7 @@ export function createQueryClient(): QueryClient {
         staleTime: Infinity,
         gcTime: 10 * 60 * 1000, // 10 minutes
         refetchOnWindowFocus: false,
-        refetchOnReconnect: false,
+        refetchOnReconnect: true,
         retry: 1,
       },
       mutations: {