fix: Tier-2 mediums — input trims, confirmations, amount normalization

More robustness fixes from the audit (the import-key pattern, lower severity):

- Trim pasted input before use/validation: network add-server URL/label,
  lite-wallet key import (+ block empty), validate-address, address-book entry.
- Confirmations for destructive/irreversible actions:
  - Address-book Delete now needs a confirming second click (no undo).
  - Console `stop` needs a confirming second `stop` (it shuts down the node).
  - Wizard "Skip" encryption needs a confirming second click (keys stored
    unencrypted).
- Send amount: normalize to 8dp (satoshi precision) on both the DRGX and USD
  inputs so digits past 8dp aren't silently dropped between the preview/review
  and what's actually sent.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/windows/console_tab.cpp

@@ -1298,6 +1298,9 @@ bool ConsoleTab::submitConsoleCommand(ConsoleCommandExecutor& exec, const std::s
         std::transform(first.begin(), first.end(), first.begin(),
                        [](unsigned char c) { return static_cast<char>(std::tolower(c)); });
     }
+    // 'stop' shuts down the node — require a confirming second 'stop'; any other command clears the pending state.
+    static bool stopConfirmPending = false;
+    if (first != "stop") stopConfirmPending = false;
     auto add = [this](const std::string& l, ConsoleChannel c) { addLine(l, c); };
     if (first == "clear" || first == "cls") {
         // View-only clear — NEVER forwarded (the lite backend's `clear` wipes tx history).
@@ -1307,6 +1310,16 @@ bool ConsoleTab::submitConsoleCommand(ConsoleCommandExecutor& exec, const std::s
         exec.printHelp(add);
     } else if (first == "quit" || first == "exit") {
         addLine(TR("console_quit_note"), ConsoleChannel::Info);
+    } else if (first == "stop") {
+        if (!stopConfirmPending) {
+            stopConfirmPending = true;
+            addLine("'stop' will shut down the node and disconnect the wallet. Type 'stop' again to confirm.",
+                    ConsoleChannel::Warning);
+        } else {
+            stopConfirmPending = false;
+            if (!exec.isReady()) addLine(TR("console_not_connected"), ConsoleChannel::Error);
+            else                 exec.submit(cmd);
+        }
     } else if (!exec.isReady()) {
         addLine(TR("console_not_connected"), ConsoleChannel::Error);
     } else {