feat: more llm provider options (google, mistral) (#28)

* feat: add google provider

* fix: default for google model

* feat: multiple providers

* fix: defaults from env for login form

* fix: add mistral to env files

* chore: delete unused code

* chore: revert database url to original

* fix: render default value for api key from env on server

* fix: type errors during compilation

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Co-authored-by: Vasily Zubarev <me@vas3k.ru>

public/logo/google.svg

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