Ask for the mnemonic and passphrase before taking the state directory lock (closes #152)

init, vault create, unlocker add, and add, import and generate secret
with --force asked for the mnemonic or passphrase, or unlocked the
vault, while holding the state directory lock, so every other command
that changes anything waited at the prompt. They now ask and unlock
first and lock after. Under the lock, unlocker add fails if the vault
was removed, or created again with another key, and refuses a GPG key
added meanwhile; a forced add of a secret created meanwhile lets go of
the lock, gets the key and locks again. secret.CreatePGPUnlocker takes
the unlocked vault; SetMnemonic and SetUnlockPassphrase are gone.

Not done: secret move between vaults still unlocks both under the lock
(#189).

Model: opus-5-5

internal/cli/generate.go

@@ -175,12 +175,6 @@ func (cli *Instance) GenerateSecret(
 		return fmt.Errorf("failed to generate random secret: %w", err)
 	}
 
-	release, err := vault.LockStateDir(cli.fs, cli.stateDir)
-	if err != nil {
-		return err
-	}
-	defer release()
-
 	// Store the secret in the vault
 	vlt, err := vault.GetCurrentVault(cli.fs, cli.stateDir)
 	if err != nil {
@@ -193,7 +187,7 @@ func (cli *Instance) GenerateSecret(
 	secretBuffer := memguard.NewBufferFromBytes([]byte(secretValue))
 	defer secretBuffer.Destroy()
 
-	err = vlt.AddSecret(secretName, secretBuffer, force)
+	err = cli.storeSecret(vlt, secretName, secretBuffer, force)
 	if err != nil {
 		return err
 	}