feat: v2 — view-key payment confirmation with live monitoring

- Payment monitor: enter private view key to track incoming payments
- Scans mempool + last 100 blocks via PHP proxy with 4-node failover
- Lightweight crypto: 30KB noble-curves bundle (Ed25519 + Keccak-256)
- Subaddress support (network byte 42 detection, a*D validation)
- Confirmation progress bar (0-10 confirmations)
- Underpayment detection
- Deadline badges (7/14/30 days) replacing minutes input
- QR code: standard colors (black on white) for wallet scanner compatibility
- QR hint positioned below QR code
- View key masked input, never stored or transmitted

index.html

@@ -44,8 +44,13 @@
       </div>
 
       <div class="field">
-        <label for="timer" data-i18n="label_timer"></label>
-        <input type="number" id="timer" data-i18n-placeholder="placeholder_timer" min="1" step="1">
+        <label data-i18n="label_timer"></label>
+        <div class="deadline-badges" id="deadlineBadges">
+          <button type="button" class="badge" data-days="7">7 <span data-i18n="days"></span></button>
+          <button type="button" class="badge" data-days="14">14 <span data-i18n="days"></span></button>
+          <button type="button" class="badge" data-days="30">30 <span data-i18n="days"></span></button>
+          <input type="number" id="timerCustom" data-i18n-placeholder="placeholder_timer_custom" min="1" step="1" class="badge-input">
+        </div>
       </div>
 
       <button class="btn btn-primary" id="generate" disabled data-i18n="btn_generate"></button>
@@ -68,6 +73,34 @@
         <a class="btn btn-secondary" id="openWallet" href="#" data-i18n="btn_open_wallet"></a>
         <button class="btn btn-secondary" id="copyAddr" data-i18n="btn_copy_addr"></button>
       </div>
+      <!-- Payment Monitor (v2) -->
+      <div class="monitor-section" id="monitorSection">
+        <button class="btn btn-monitor" id="monitorToggle">
+          <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <rect x="3" y="11" width="18" height="11" rx="2" ry="2"/>
+            <path d="M7 11V7a5 5 0 0 1 10 0v4"/>
+          </svg>
+          <span data-i18n="btn_monitor"></span>
+        </button>
+        <div class="monitor-panel" id="monitorPanel">
+          <div class="field">
+            <label for="viewKey" data-i18n="label_view_key"></label>
+            <input type="text" id="viewKey" data-i18n-placeholder="placeholder_view_key" spellcheck="false" autocomplete="off" class="mono-masked">
+            <div class="view-key-hint" data-i18n="hint_view_key"></div>
+          </div>
+          <button class="btn btn-primary" id="startMonitor" disabled data-i18n="btn_start_monitor"></button>
+          <div class="monitor-status" id="monitorStatus">
+            <div class="status-indicator" id="statusIndicator"></div>
+            <div class="status-text" id="statusText"></div>
+            <div class="confirmations-bar" id="confirmationsBar">
+              <div class="confirmations-fill" id="confirmationsFill"></div>
+              <span class="confirmations-text" id="confirmationsText"></span>
+            </div>
+          </div>
+          <button class="btn btn-secondary" id="stopMonitor" data-i18n="btn_stop_monitor"></button>
+        </div>
+      </div>
+
       <button class="btn btn-primary btn-new" id="newRequest" data-i18n="btn_new_request"></button>
     </div>
   </main>
@@ -93,5 +126,6 @@
   <script src="lib/qrcode.min.js"></script>
   <script src="i18n.js"></script>
   <script src="app.js"></script>
+  <script src="monitor.js"></script>
 </body>
 </html>