fix(desktop): require session ids for scoped gateway events (#42178)

* fix(desktop): require session ids for scoped gateway events

Drop unscoped stream, tool, and subagent events in the desktop renderer so async activity cannot attach to whichever chat is currently focused.

* fix(desktop): preserve unscoped session info events

Keep session.info out of the scoped-event drop list so global desktop runtime broadcasts still initialize UI state before a session is active.

apps/desktop/src/app/session/hooks/use-message-stream.ts

@@ -14,6 +14,7 @@ import {
   upsertToolPart
 } from '@/lib/chat-messages'
 import { coerceGatewayText, coerceThinkingText, normalizePersonalityValue } from '@/lib/chat-runtime'
+import { gatewayEventRequiresSessionId } from '@/lib/gateway-events'
 import { triggerHaptic } from '@/lib/haptics'
 import { isProviderSetupErrorMessage } from '@/lib/provider-setup-errors'
 import { setClarifyRequest } from '@/store/clarify'
@@ -613,6 +614,9 @@ export function useMessageStream({
     (event: RpcEvent) => {
       const payload = event.payload as GatewayEventPayload | undefined
       const explicitSid = event.session_id || ''
+      if (!explicitSid && gatewayEventRequiresSessionId(event.type)) {
+        return
+      }
       const sessionId = explicitSid || activeSessionIdRef.current
       const isActiveEvent = !!sessionId && sessionId === activeSessionIdRef.current