Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/transport/subscription-worker/components/heartbeat-requests-manager.ts`:
- Around line 183-186: The attachClientListeners method currently overwrites
this.clientAbortControllers[client.identifier] without aborting any existing
controller, which allows duplicate heartbeat/presence handlers; update
attachClientListeners to check this.clientAbortControllers[client.identifier]
and if an existing AbortController exists, call abort() (and optionally remove
it) before creating and storing the new AbortController for the PubNubClient,
and ensure any listener cleanup tied to the AbortSignal runs so duplicate
handlers are not left registered.

In `@src/transport/subscription-worker/components/subscribe-requests-manager.ts`:
- Around line 372-375: The attachClientListeners function currently overwrites
this.clientAbortControllers[client.identifier] with a new AbortController
without aborting any prior controller, which allows duplicate handlers to
remain; before creating and assigning a new AbortController in
attachClientListeners, check for an existing controller at
this.clientAbortControllers[client.identifier], call .abort() on it (and
optionally delete it) to cancel / clean up previous listeners/work, then create
and assign the new AbortController so re-attaching won’t leave duplicate
handlers enqueued.

In `@src/transport/subscription-worker/subscription-worker-middleware.ts`:
- Around line 232-248: The tokenChangeChain currently becomes permanently
rejected if parsedAccessToken or scheduleEventPost rejects; wrap the promise
sequence attached to tokenChangeChain so that errors are caught and handled
(e.g., log via the worker logger) and the chain returns a resolved value to
allow future updates to run; specifically, update the code that chains
parsedAccessToken(...) -> then(...) -> scheduleEventPost(updateEvent) on
tokenChangeChain to append a .catch(err => { /* log with context about
updateEvent/clientIdentifier */ }) that swallows or converts the error into a
resolved outcome so tokenChangeChain remains recoverable while still recording
the failure.

In `@test/integration/shared-worker/shared-worker.test.ts`:
- Line 1637: The test uses it.only which will cause all other tests to be
skipped; remove the .only from the it.only call (the test named "should receive
timeout presence events when browser tabs are closed") so it becomes a normal
it(...) test, ensuring the full suite runs in CI and eliminating this debugging
artifact.

---

Outside diff comments:
In `@src/transport/subscription-worker/components/pubnub-clients-manager.ts`:
- Around line 211-214: In unregisterClient (pubnub-clients-manager.ts) avoid
calling splice with -1 by checking that the client exists before removing:
locate the code that accesses this.clientBySubscribeKey[client.subKey] and
computing clientIdx = clientsBySubscribeKey.indexOf(client) and add a guard like
clientIdx !== -1 (or use a filter to remove the exact reference) before calling
clientsBySubscribeKey.splice; mirror the same presence check used in
suspendClient to prevent accidentally removing the last array element when the
client isn't found.

In `@src/transport/subscription-worker/subscription-worker-middleware.ts`:
- Around line 440-445: The 'shared-worker-client-suspended' message is not being
filtered by clientIdentifier, causing suspend events from other clients to
reject this instance's in-flight requests; update the message handling so the
condition that checks data.clientIdentifier !==
this.configuration.clientIdentifier also applies to data.type ===
'shared-worker-client-suspended', and modify the logic that rejects pending
callbacks (the method that currently rejects all pending callbacks when handling
'shared-worker-client-suspended') to only reject callbacks associated with the
suspended client's identifier (use the same clientIdentifier field on the
pending callback entries) instead of rejecting every outstanding callback.

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@src/transport/subscription-worker/components/pubnub-clients-manager.ts`:
- Around line 178-194: The reactivateClient method can overwrite an existing
this.clients[client.identifier] and leak the previous AbortController/listeners;
update reactivateClient to first check if this.clients[client.identifier]
already exists and either (a) if already active, return early (no-op) or (b) if
you intend to replace, call abort() on the existing entry's abortController and
clean up subscriptions before overwriting; ensure you also avoid duplicating
entries in this.clientBySubscribeKey[client.subKey] when reactivating and only
call subscribeOnClientEvents and dispatchEvent after safely replacing or
confirming activation.