Add Visage v2.7.0 - facial recognition plugin

[cc1234475]

What's new in v2.7.0

Features

• Stash sync button in BackendSettings — trigger a Stash performer index sync directly from the plugin settings modal (local backend only, visible when Stash URL is configured)

Fixes

• Skip StashDB scrape for stash-synced performers — performers already synced from Stash no longer trigger redundant StashDB lookups
• Handle URL and base64 performer portrait images — performer images from external sources now render correctly regardless of format

Included since v2.6.0

• Full internationalization across 35 languages
• Localized UI keeps Visage buttons visible regardless of Stash language
• Localized error/warning toasts and accessibility labels