Rewrote the user guide against the code:
- No competitor is named anywhere; the opening, the derivation-path note
and the FAQ make their points without them.
- Removed the false "no remote phishing blocklist" claim. The blocklist
fetch is documented as what it is: a bundled copy plus a live fetch on
background startup and every 24h.
- External Services now lists all five destinations (RPC, Blockscout,
CoinDesk, phishing blocklist, Etherscan label lookup) with what is sent
and when.
- Password statements cover transaction signing, message and typed-data
signing, private key export and wallet deletion.
- Add Wallet is documented as the three tabs that exist (phrase, private
key, xprv), not a nonexistent link.
- Settings matches the shipped screen: tracked tokens, network selector,
theme, UTC timestamps, About.
- Corrected token-list size, token discovery behaviour, Sepolia support,
and the send/approval button labels.
