fix(api): /ping -> /api/ping

docs: small doc updates

feat(api): init redis session backend

chore(api): add actix-session dep

chore(api): format Cargo.toml

fix(api): update dev-launch.sh with redis url in wanted format

fix(api): update dev-launch.sh with valid cookie signing key

feat(api): add redis configuration to docker-compose.dev.yaml

chore: cleanup old unneeded files

chore(api): update dev scripts

fix(api): check if user exists before hashing password on registration

feat(api): reimpl user registration

feat(shared): a few database and argon errors

fix(api): skip user model password field

fix(api): avoid duplicate user details at the db level

fix(api): NewUser -> InsertableUser

chore(api): argon2 dep, uuid dep absolute fuckery

chore(api): add email_address dep for validating emails

fix(shared): fix error/api visibility

feat(shared): serialize APIError