Settings grew tall enough that the user had to scroll past a dozen
cards to reach Prices, Sites or About. Split it into six named
sections (Security, Session, Wallet, Prices, Sites, About) with a
chip nav row at the top; only one section is visible at a time and
the choice persists across restarts.
Adds an About card that names the wallet, the aegis.x front-door
site and the silentmode.st umbrella, so support triage has a
one-click way to reach either from within the panel.
Includes the accumulated 0.7.x-0.8.1 wallet work that was already
shipping on OTA (CashTokens/BCMR, imported-wallet spend, siascan
integration, consolidate, currency picker, footer update chip).
