v0.26.1 — show auto-generated values on deploy page

- Pre-generate domain + secret field values when deploy page loads,
  so user sees actual domain and masked passwords (with reveal button)
  before deploying. Same values submitted as hidden inputs → saved to app.yaml.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

controller/internal/stacks/deploy.go

@@ -114,12 +114,17 @@ func (m *Manager) DeployStack(req DeployRequest) (string, error) {
 			value = m.cfg.Customer.Domain
 
 		case "secret":
-			// Always auto-generate, user never sees these
-			generated, err := generateValue(field.Generate)
-			if err != nil {
-				return "", fmt.Errorf("generating %s: %w", field.EnvVar, err)
+			// Use pre-generated value if provided by the deploy page (same value the user saw),
+			// otherwise fall back to generating a fresh one.
+			if userVal, ok := req.Values[field.EnvVar]; ok && userVal != "" {
+				value = userVal
+			} else {
+				generated, err := generateValue(field.Generate)
+				if err != nil {
+					return "", fmt.Errorf("generating %s: %w", field.EnvVar, err)
+				}
+				value = generated
 			}
-			value = generated
 
 		case "password":
 			// Password fields MUST be filled by the user (via typing or Generálás button).
@@ -366,6 +371,37 @@ func (m *Manager) LoadAppConfigByName(stackName string) *AppConfig {
 	return LoadAppConfig(stackDir)
 }
 
+// PreviewDeployValues generates the auto-field values that will be used at deploy time:
+// domain from controller config and freshly-generated secrets. These values are shown
+// on the deploy page so the user can see (and note down) their passwords before deploying.
+// Pass them back in DeployRequest.Values so the same values are saved to app.yaml.
+func (m *Manager) PreviewDeployValues(name string) (map[string]string, error) {
+	stack, ok := m.GetStack(name)
+	if !ok {
+		return nil, fmt.Errorf("stack %q not found", name)
+	}
+	stackDir := filepath.Dir(stack.ComposePath)
+	meta := LoadMetadata(stackDir)
+
+	result := make(map[string]string)
+	for _, field := range meta.DeployFields {
+		switch field.Type {
+		case "domain":
+			result[field.EnvVar] = m.cfg.Customer.Domain
+		case "secret":
+			if field.Generate == "" {
+				continue
+			}
+			val, err := generateValue(field.Generate)
+			if err != nil {
+				return nil, fmt.Errorf("generating preview for %s: %w", field.EnvVar, err)
+			}
+			result[field.EnvVar] = val
+		}
+	}
+	return result, nil
+}
+
 // --- App config persistence ---
 
 func LoadAppConfig(stackDir string) *AppConfig {