v0.6.0 — One System card

Live was four cards where one will do. Rate, power flow and the supporting readings are all "what is the system doing right now", so they are now a single System card with three tiers of prominence:

1. the rate in force, with the tariff ribbon
2. what is flowing — solar, grid, battery, home
3. the supporting readings, in smaller muted type below a hairline

Live is now System · Performance · Battery.

Includes v0.5.2's mobile overflow fix and v0.5.3's completed-day effective rate. module_url is ?v=0.6.0.