Merge "Create new wallet" and "Import recovery phrase" into one
"Add wallet" screen. The recovery phrase textarea starts empty.
A clickable die button generates a random phrase and shows a
backup warning. Users who already have a phrase just paste it.
Welcome screen simplified to two options: "Add wallet" and
"Import private key". README updated to match.
Replace jargon-heavy terminal-style UI with plain-language views.
New data model: wallets (HD or private key) contain addresses.
Main view lists all addresses grouped by wallet with balances.
HD wallets get a "+" to add addresses; key wallets have one.
Two import paths: recovery phrase and private key.
All labels use plain English, full-sentence errors, inline help
text. README updated with full UI philosophy, language guide,
data model, and navigation docs.
