feat: offline support tier 3 — mutation queue and image caching

Paused mutations (read/save toggles) are now persisted to IndexedDB
and automatically resumed on reconnection or page reload via TanStack
Query's offlineFirst networkMode. Service worker caches images with
CacheFirst strategy (500 entries, 7-day expiry) for offline reading.

1 files changed, 3 insertions, 0 deletions

diff --git a/apps/web/lib/queries/use-entry-state-mutations.ts b/apps/web/lib/queries/use-entry-state-mutations.ts
index 80bab79..b5f64e9 100644
--- a/apps/web/lib/queries/use-entry-state-mutations.ts
+++ b/apps/web/lib/queries/use-entry-state-mutations.ts
@@ -3,6 +3,7 @@
 import { useMutation, useQueryClient } from "@tanstack/react-query"
 import { createSupabaseBrowserClient } from "@/lib/supabase/client"
 import { queryKeys } from "./query-keys"
+import { MUTATION_KEYS } from "@/lib/query-client"
 import type { TimelineEntry } from "@/lib/types/timeline"
 import type { InfiniteData } from "@tanstack/react-query"
 
@@ -11,6 +12,7 @@ export function useToggleEntryReadState() {
   const queryClient = useQueryClient()
 
   return useMutation({
+    mutationKey: MUTATION_KEYS.toggleEntryReadState,
     mutationFn: async ({
       entryIdentifier,
       isRead,
@@ -84,6 +86,7 @@ export function useToggleEntrySavedState() {
   const queryClient = useQueryClient()
 
   return useMutation({
+    mutationKey: MUTATION_KEYS.toggleEntrySavedState,
     mutationFn: async ({
       entryIdentifier,
       isSaved,