feat(v1.2.1): add security monitoring components

- Add Storage Indicator (browser localStorage/sessionStorage monitor)
- Add Security Warnings (educational panel on JS limitations)
- Add Clipboard Tracker (copy event detection with clear function)
- Add data-sensitive attributes to sensitive fields

Security Features:
- Real-time storage monitoring with sensitive data highlighting
- Clipboard activity tracking with character count
- System clipboard clearing functionality
- Collapsible floating widgets (non-intrusive)
- Auto-refresh storage display every 2s
- Educational warnings about GC, string immutability, etc.

UI/UX:
- Floating widgets: Storage (bottom-right), Warnings (bottom-left), Clipboard (bottom-right stacked)
- Color-coded alerts (red=sensitive, orange=activity, yellow=warnings)
- Responsive and clean design with TailwindCSS

src/main.tsx

@@ -1,3 +1,23 @@
+// Suppress OpenPGP.js AES cipher warnings
+const originalWarn = console.warn;
+const originalError = console.error;
+
+console.warn = (...args: any[]) => {
+  const msg = args[0]?.toString() || '';
+  if (msg.includes('AES-CBC') || msg.includes('AES-CTR') || msg.includes('authentication')) {
+    return;
+  }
+  originalWarn.apply(console, args);
+};
+
+console.error = (...args: any[]) => {
+  const msg = args[0]?.toString() || '';
+  if (msg.includes('AES-CBC') || msg.includes('AES-CTR') || msg.includes('authentication')) {
+    return;
+  }
+  originalError.apply(console, args);
+};
+
 import { StrictMode } from 'react'
 import { createRoot } from 'react-dom/client'
 import './index.css'