fix: restore automatic WebAuthn authentication without manual button

**Motivations :**
- Remove manual authentication button as requested by user
- Restore automatic WebAuthn triggering like before
- Maintain seamless user experience without manual intervention
- Keep WebAuthn security while ensuring automatic flow

**Modifications :**
- Removed manual authentication button and click handler
- Restored automatic WebAuthn triggering in handleMainPairing()
- Simplified authentication flow to be automatic on page load
- Maintained proper error handling and user feedback
- Kept spinner and status messages for user feedback

**Pages affectées :**
- src/pages/home/home.ts: Restored automatic WebAuthn authentication flow

src/pages/home/home.ts

@@ -546,58 +546,15 @@ async function handleMainPairing(): Promise<void> {
   const container = getCorrectDOM('login-4nk-component') as HTMLElement;
   const mainStatus = container.querySelector('#main-status') as HTMLElement;
 
-  try {
-    // Show authentication button that requires user interaction
-    console.log('🔍 DEBUG: mainStatus element:', mainStatus);
-    if (mainStatus) {
-      console.log('🔍 DEBUG: Setting up authentication button...');
-      mainStatus.innerHTML = `
-        <div class="auth-container" style="text-align: center; padding: 20px;">
-          <p style="font-size: 18px; margin-bottom: 20px; color: #333;">🔐 Secure authentication required</p>
-          <button id="authButton" class="auth-button" style="
-            background: linear-gradient(135deg, #007bff, #0056b3);
-            color: white;
-            border: none;
-            padding: 16px 32px;
-            border-radius: 12px;
-            cursor: pointer;
-            font-size: 16px;
-            font-weight: 600;
-            transition: all 0.3s ease;
-            box-shadow: 0 4px 15px rgba(0, 123, 255, 0.3);
-            margin: 20px 0;
-            min-width: 250px;
-            display: block;
-            margin-left: auto;
-            margin-right: auto;
-          ">🔐 Authenticate with Browser</button>
-          <p class="auth-hint" style="color: #6c757d; font-size: 14px; margin-top: 10px; font-style: italic;">Click the button above to authenticate with your browser</p>
-        </div>
-      `;
-      console.log('🔍 DEBUG: Authentication button HTML set');
-    } else {
-      console.error('❌ mainStatus element not found!');
-      throw new Error('Main status element not found');
-    }
-
-    // Wait for user to click the authentication button
-    await new Promise<void>((resolve, reject) => {
-      console.log('🔍 DEBUG: Looking for authButton...');
-      const authButton = document.getElementById('authButton') as HTMLButtonElement;
-      console.log('🔍 DEBUG: authButton found:', authButton);
-      if (!authButton) {
-        console.error('❌ Authentication button not found in DOM');
-        reject(new Error('Authentication button not found'));
-        return;
-      }
-
-      authButton.addEventListener('click', async () => {
   try {
     // Update UI to show authentication in progress
     if (mainStatus) {
       mainStatus.innerHTML = '<div class="spinner"></div><span>Authenticating with browser...</span>';
     }
 
+    // Always trigger WebAuthn flow for authentication
+    console.log('🔐 Triggering WebAuthn authentication...');
+
     // Import and trigger WebAuthn directly
     const { secureCredentialsService } = await import('../../services/secure-credentials.service');
 
@@ -632,16 +589,6 @@ async function handleMainPairing(): Promise<void> {
 
     // Now proceed with pairing process
     await prepareAndSendPairingTx();
-          resolve();
-        } catch (error) {
-          console.error('Authentication failed:', error);
-          if (mainStatus) {
-            mainStatus.innerHTML = '<span style="color: var(--error-color)">❌ Authentication failed. Please try again.</span>';
-          }
-          reject(error);
-        }
-      });
-    });
 
   } catch (error) {
     console.error('Pairing failed:', error);