fix(pages): populate defaults before translation overlay

Add ensureTemplateDefaults function that fills navigation labels and section headlines with template-specific defaults before applying translation overlay. Ensures these fields are present in base config JSON so translations can override them via deep-merge. Fixes issue where translated labels wouldn't apply because base config had empty strings instead of default values. Prevents templates from falling back to hardcoded English text.

routers/web/pages/pages.go

@@ -1174,6 +1174,11 @@ func detectPageLanguage(ctx *context.Context, config *pages_module.LandingConfig
 // applyLanguageOverlay loads the translation for the detected language and merges it onto config.
 // Sets template data for the language switcher and returns the (possibly merged) config.
 func applyLanguageOverlay(ctx *context.Context, repo *repo_model.Repository, config *pages_module.LandingConfig) *pages_module.LandingConfig {
+	// Ensure navigation labels and section headlines are populated with
+	// template-specific defaults so they are present in the base config
+	// for deep-merge (and so templates never fall back to hardcoded English).
+	ensureTemplateDefaults(config)
+
 	if len(config.I18n.Languages) == 0 {
 		return config
 	}
@@ -1215,6 +1220,44 @@ func applyLanguageOverlay(ctx *context.Context, repo *repo_model.Repository, con
 	return merged
 }
 
+// ensureTemplateDefaults fills in empty navigation labels and section headlines
+// with template-specific defaults so they are always present for serialization
+// and deep-merge. This ensures the base config JSON contains these keys, making
+// them available for the translation overlay to override.
+func ensureTemplateDefaults(config *pages_module.LandingConfig) {
+	defaults := pages_module.TemplateDefaultLabels(config.Template)
+	nav := &config.Navigation
+	if nav.LabelValueProps == "" {
+		nav.LabelValueProps = defaults.LabelValueProps
+	}
+	if nav.LabelFeatures == "" {
+		nav.LabelFeatures = defaults.LabelFeatures
+	}
+	if nav.LabelPricing == "" {
+		nav.LabelPricing = defaults.LabelPricing
+	}
+	if nav.LabelBlog == "" {
+		nav.LabelBlog = defaults.LabelBlog
+	}
+	if nav.LabelGallery == "" {
+		nav.LabelGallery = defaults.LabelGallery
+	}
+	if nav.LabelCompare == "" {
+		nav.LabelCompare = defaults.LabelCompare
+	}
+	// Section headlines — fill empty headlines with sensible defaults
+	// so they appear in the base JSON and can be overridden by translations.
+	if config.Blog.Enabled && config.Blog.Headline == "" {
+		config.Blog.Headline = "Latest Posts"
+	}
+	if config.Gallery.Enabled && config.Gallery.Headline == "" {
+		config.Gallery.Headline = "Gallery"
+	}
+	if config.Comparison.Enabled && config.Comparison.Headline == "" {
+		config.Comparison.Headline = "How We Compare"
+	}
+}
+
 // ApproveExperiment handles the email approval link for an A/B test experiment
 func ApproveExperiment(ctx *context.Context) {
 	handleExperimentAction(ctx, true)