Choose your own block explorer; flatten How it works

- Settings → Block explorer: pick mempool.space (default, with
  blockstream.info as a silent failover), blockstream.info only, or a
  custom Esplora/electrs REST URL (e.g. your own node). The realtime
  WebSocket only applies to mempool.space; other explorers fall back to
  polling. Switching rebuilds the API and rescans. Replaces the old
  undocumented explorer-proxy hack.
- How it works: merge the "For the technically curious" disclosure into
  the main body so it's all visible under "The basics", and dedupe the
  overlapping no-server/offline sentences. Mentions the new explorer
  setting.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

1 files changed, 8 insertions, 6 deletions

diff --git a/src/i18n.js b/src/i18n.js
index 5289974..67eb29b 100644
--- a/src/i18n.js
+++ b/src/i18n.js
@@ -63,12 +63,10 @@ const STR = {
     installApp: 'Install app',
     hiwBasicsTitle: 'The basics',
     hiwBasics1: 'When you make a wallet, the page generates twelve random words. Those words are the key to your wallet. Anyone who has them can spend the coins, so write them down on paper and keep them somewhere only you can get to.',
-    hiwBasics2: 'Everything happens on your device. There’s no server keeping your balance and nobody holding your coins for you. The words stay in your browser, and the page still works when you’re offline.',
-    hiwBasics4: 'If you lose the twelve words and don’t have a backup, the coins are gone for good. There’s no reset link and no one to call, so back them up before you put money in.',
-    hiwTechTitle: 'For the technically curious',
-    hiwTech1: 'There’s no backend. This page is one static HTML file, so nothing on a server ever touches your keys. It reads balances and history from a public block explorer (mempool.space).',
-    hiwTech2: 'It sticks to the usual Bitcoin standards: a 12-word BIP39 recovery phrase, with BIP84 native SegWit (P2WPKH) keys derived at m/84\'/0\'/0\'. If this wallet ever vanishes, drop the same phrase into Electrum, Sparrow, or any other standard wallet and your coins will be right there.',
-    hiwTech4: 'You can save this page and open it straight off your hard drive with no connection at all.',
+    hiwBasics2: 'If you lose the twelve words and don’t have a backup, the coins are gone for good. There’s no reset link and no one to call, so back them up before you put money in.',
+    hiwBasics3: 'There’s no server and no account. The whole app is a single page that runs in your browser, so nobody holds your coins and nothing on a server ever sees your keys. To show your balance and history it reads from a public block explorer (mempool.space by default, or your own node if you set one in Settings).',
+    hiwBasics4: 'You can even save this page and open it straight from your computer with no internet at all. It keeps working offline.',
+    hiwBasics5: 'It follows the usual Bitcoin standards (a 12-word BIP39 phrase and BIP84 native SegWit keys), so if this site ever disappears you can restore the same phrase in Sparrow, Electrum, or any other standard wallet and your coins will be right there.',
     balance: 'Balance',
     pending: 'Pending',
     tabReceive: 'Receive',
@@ -153,6 +151,10 @@ const STR = {
     rescanDesc: 'Your current address updates automatically. Rescan only if a payment was sent to an old (reused) address and isn’t showing.',
     rescanWallet: 'Rescan wallet',
     scanning: 'Scanning…',
+    explorer: 'Block explorer',
+    explorerDesc: 'The server this wallet queries for balances and history. Use blockstream.info, or point it at your own node for maximum privacy.',
+    explorerUrl: 'Server URL',
+    explorerUrlHint: 'Esplora / electrs REST base, e.g. https://mempool.space/api',
     deviceSync: 'Device sync',
     deviceSyncDesc: 'Keep this wallet in sync across your devices by storing an encrypted copy on a Nostr relay — only a device with your seed can read it. Turn it off to keep everything on this device.',
     syncAcross: 'Sync across devices',