fix: remove timeouts from error toasts so they persist until dismissed (#9543)

## Summary

Remove `life` (timeout) property from all error-severity toast calls so
they persist until manually dismissed, preventing users from missing
important error messages.

## Changes

- **What**: Removed `life` property from 86 error toast calls across 46
files. Error toasts now use PrimeVue's default behavior (no
auto-dismiss). Non-error toasts (success, warn, info) are unchanged.
- Also fixed a pre-existing lint issue in `TaskListPanel.vue` (`import {
t } from '@/i18n'` → `useI18n()`)

## Review Focus

- One conditional toast in `useMediaAssetActions.ts` intentionally keeps
`life` because its severity alternates between `warn` and `error`

Fixes
https://www.notion.so/comfy-org/Implement-Remove-timeouts-for-all-error-toasts-31b6d73d365081cead54fddc77ae7c3d

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9543-fix-remove-timeouts-from-error-toasts-so-they-persist-until-dismissed-31c6d73d365081fa8d30f6366e9bfe38)
by [Unito](https://www.unito.io)

src/core/graph/subgraph/promotionUtils.ts

@@ -81,8 +81,7 @@ function getParentNodes(): SubgraphNode[] {
     useToastStore().add({
       severity: 'error',
       summary: t('g.error'),
-      detail: t('subgraphStore.promoteOutsideSubgraph'),
-      life: 2000
+      detail: t('subgraphStore.promoteOutsideSubgraph')
     })
     return []
   }