perplexica: deprecate or fix

[aslilac]

• perplexica seems to have been renamed to vane
• the vane docker image is still receiving updates but the perplexica
• it uses the next.js default favicon because the upstream project does not have an official icon
• it doesn't even show a download count on the registry. does anyone use this?

[linear-code]

ENG-3381

[matifali]

cc: @phorcys420