Vault unlock page accepts passwords that don't meet the password policy #4320

Initial Checklist

• I understand this is a bug report and questions should be posted in the Community Discussions
• I searched issues and couldn’t find anything (or linked relevant results below)

Bug Description

Since #3537, the "Set password" step on the vault unlock page shows the password policy, but doesn't enforce it: the rules are shown as not met and the password is still accepted. Creating an encrypted folder blocks it as expected.

Reproduction Steps

1. Have an encrypted folder without a saved passphrase (e.g. when creating it reported that its passphrase was not saved)
2. Open it, the unlock page shows "Set password"
3. Type ab

Expected Outcome

"Set password" stays disabled until the rules are met.

Actual Outcome

The rules show "Requirement not met", but the button is enabled and the vault gets set up with ab. UnlockVault.vue doesn't listen to update:valid from VaultSetup.