fix(desktop): rename settings row to Password Backup per spec

Tyler's spec names the settings entry "Password Backup". Rename the
row title and align its description (password, not passphrase) plus
the two doc comments that referenced the old row name. No behavior
change; test ids unchanged.

Co-authored-by: Tyler Longwell <tlongwell@block.xyz>
Signed-off-by: Tyler Longwell <tlongwell@block.xyz>

desktop/src/features/onboarding/lib/encryptedBackup.ts

@@ -1,6 +1,6 @@
 /**
  * Pure state model for the encrypted-key-backup (NIP-49) creation flow,
- * shared by the onboarding BackupStep and the settings Encrypted backup row.
+ * shared by the onboarding BackupStep and the settings Password Backup row.
  *
  * All validation and phase logic lives here so it can be unit-tested without
  * React. Hosts wire the reducer to the Tauri commands

desktop/src/features/onboarding/ui/EncryptedBackupCreator.tsx

@@ -29,7 +29,7 @@ type EncryptedBackupCreatorProps = {
 
 /**
  * Passphrase-first NIP-49 backup creation flow, shared by the onboarding
- * BackupStep and the settings Encrypted backup row.
+ * BackupStep and the settings Password Backup row.
  *
  * The raw private key never enters this component: it collects a passphrase,
  * asks Rust to create + persist the encrypted backup, and displays the

desktop/src/features/settings/ui/ProfileSettingsCard.tsx

@@ -189,9 +189,9 @@ function EncryptedBackupRow() {
     <div className="px-4 py-3" data-testid="profile-encrypted-backup-row">
       <div className="flex items-center justify-between gap-4">
         <div className="min-w-0 space-y-1">
-          <p className="text-sm font-medium">Encrypted backup</p>
+          <p className="text-sm font-medium">Password Backup</p>
           <p className="text-sm text-muted-foreground">
-            Protect your key with a passphrase and save a recoverable backup.
+            Protect your key with a password and save a recoverable backup.
           </p>
         </div>
         <button