2023 v2 features & bugfixes

[benswift]

• add "BYO replicate token" functionality
• add a proper signup process (probs with admin approval)
• migrate to phoenix v1.7 (maybe from scratch - removing PETAL?)
• refactor network creation UI (maybe even multi-path networks)
• stats/dashboard view (not just a HUD)
• doco (esp. for non-Ben uses)