fix: Vue 3 lifecycle + Element Plus slot syntax across renderer components

Migrate remaining Vue 2 remnants: beforeDestroy → beforeUnmount (11 components),
slot="name"/slot-scope → <template #name> named slots (6 components),
and replace `as any` with typed WrappedIpcListener in preload.ts.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>