chore(auth): add 2FA database logging

- capture and log insert errors during 2FA code generation

- print verification queries and lookup parameters to console

shop/lib/actions/auth.ts

@@ -185,9 +185,16 @@ async function send2FACodeInternal(userId: string, deviceHash: string, email: st
     .eq('device_hash', deviceHash)
 
   // Neuen Code speichern
-  await adminClient
+  const { data: insData, error: insError } = await adminClient
     .from('device_verification_codes')
     .insert({ user_id: userId, code, device_hash: deviceHash, expires_at: expiresAt })
+    .select()
+
+  if (insError) {
+    console.error("2FA CODE INSERT ERROR:", insError)
+  } else {
+    console.log("2FA CODE INSERTED:", code, insData)
+  }
 
   // Mail senden
   await sendMail({
@@ -222,6 +229,7 @@ export async function verifyDevice2FA(userId: string, code: string, deviceHash:
     const cleanCode = code.trim()
 
     // Code prüfen (unter Berücksichtigung von Leerzeichen & device_hash)
+    console.log("VERIFYING 2FA: userId =", userId, "code =", cleanCode)
     const { data: codeEntries, error: codeError } = await adminClient
       .from('device_verification_codes')
       .select('*')
@@ -231,6 +239,7 @@ export async function verifyDevice2FA(userId: string, code: string, deviceHash:
       .limit(1)
 
     const codeEntry = codeEntries && codeEntries.length > 0 ? codeEntries[0] : null
+    console.log("VERIFY 2FA DB RESULT: entry =", codeEntry, "error =", codeError)
 
     if (codeError || !codeEntry) {
       // Doppelklick- & Race-Condition Schutz: Prüfen ob das Gerät eben bereits verifiziert wurde