fix: KVEditor effect dependency uses stable JSON serialization

Replace the flawed join-based comparison (entryKeys.join(',')) with
JSON.stringify() to properly handle keys containing commas. The previous
implementation could produce false equality when different key sets
shared the same comma-separated representation (e.g., 'a,b' key vs
separate 'a' and 'b' keys).

This ensures the effect fires correctly when keys change, fixing silent
failures to update derived state.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Docs/Tasks.md

@@ -1,23 +1,3 @@
-### TASK-PERF-02 — `useSchedule` Exposes No `refresh` Function
-
-**Where found**
-`frontend/src/hooks/useSchedule.ts`. The hook fetches the import schedule on mount and exposes no way to re-fetch. After a `PUT /api/blocklists/schedule` from a different component or tab, the displayed schedule data stays stale until the user navigates away and back.
-
-**Goal**
-Expose a `refresh` callback from `useSchedule`, following the same pattern as `useListData` and other hooks. The `BlocklistsPage` (or whichever component saves schedule changes) should call `refresh()` after a successful save, and after `runImportNow()` completes.
-
-**Possible traps and issues**
-- `useSchedule` currently uses a simple `useEffect` on mount. Adding `refresh` means converting the internal fetch into a `useCallback` and calling it from the effect.
-- Ensure the `AbortController` pattern is applied correctly when adding `refresh`.
-
-**Docs changes needed**
-None required.
-
-**Why this is needed**
-After saving a new schedule the user sees the old schedule until they reload the page. This makes the save feel broken even when it succeeded.
-
----
-
 ### TASK-QUALITY-01 — `KVEditor` Uses `entryKeys.join(",")` as Effect Dependency
 
 **Where found**