fix: support phone pairing on QR login page

src/controllers/sessionController.js

@@ -363,10 +363,9 @@ const requestPairingCode = async (req, res) => {
       },
     }
   */
-  const sessionId = req.params.sessionId
   try {
     const { phoneNumber, showNotification = true } = req.body
-    const client = sessions.get(sessionId)
+    const client = sessions.get(req.params.sessionId)
     if (!client) {
       return res.json({ success: false, message: 'session_not_found' })
     }
@@ -375,11 +374,37 @@ const requestPairingCode = async (req, res) => {
       client.emit('code', code)
       return code
     })
-    const result = await client.requestPairingCode(phoneNumber, showNotification)
+
+    // WhatsApp Web may initially expose only the QR flow. Switch the page to
+    // phone-number login before invoking the internal pairing API.
+    await client.pupPage.evaluate(() => {
+      const labels = [
+        'Log in with phone number',
+        'Inloggen met telefoonnummer',
+      ]
+      const element = [...document.querySelectorAll('div,button,a,span')].find((node) =>
+        labels.includes(node.textContent.trim()),
+      )
+      if (element) element.click()
+    })
+    await new Promise((resolve) => setTimeout(resolve, 500))
+
+    // Drive the WhatsApp Web module directly in this Puppeteer page. This is
+    // intentionally kept here until the public wrapper handles this flow reliably.
+    const result = await client.pupPage.evaluate(
+      async (phoneNumber, showNotification) => {
+        const api = window.require('WAWebAltDeviceLinkingApi')
+        api.setPairingType('ALT_DEVICE_LINKING')
+        await api.initializeAltDeviceLinking()
+        return api.startAltLinkingFlow(phoneNumber, showNotification)
+      },
+      phoneNumber,
+      showNotification,
+    )
     res.json({ success: true, result })
   } catch (error) {
-    logger.error({ sessionId, err: error }, 'Failed to request pairing code')
-    res.status(500).json({ success: false, error: error.message })
+    logger.error({ sessionId: req.params.sessionId, err: error }, 'Failed to request pairing code')
+    sendErrorResponse(res, 500, error.message)
   }
 }