feat(pages): add blog section support to landing page templates

Add blog section configuration and rendering to landing pages. Includes:
- New BlogSectionConfig with headline, max posts, and excerpt options
- Logo source selection (URL, repo avatar, or org avatar)
- Recent blog posts display with featured images
- Navigation links to blog section
- Absolute repo URLs for custom domain support

modules/pages/config.go

@@ -44,6 +44,9 @@ type LandingConfig struct {
 	// CTA section
 	CTASection CTASectionConfig `yaml:"cta_section,omitempty"`
 
+	// Blog section
+	Blog BlogSectionConfig `yaml:"blog,omitempty"`
+
 	// Footer
 	Footer FooterConfig `yaml:"footer,omitempty"`
 
@@ -62,9 +65,10 @@ type LandingConfig struct {
 
 // BrandConfig represents brand/identity settings
 type BrandConfig struct {
-	Name    string `yaml:"name,omitempty"`
-	LogoURL string `yaml:"logo_url,omitempty"`
-	Tagline string `yaml:"tagline,omitempty"`
+	Name       string `yaml:"name,omitempty"`
+	LogoURL    string `yaml:"logo_url,omitempty"`
+	LogoSource string `yaml:"logo_source,omitempty"` // "url" (default), "repo", or "org" — selects avatar source
+	Tagline    string `yaml:"tagline,omitempty"`
 }
 
 // HeroConfig represents hero section settings
@@ -145,6 +149,16 @@ type CTASectionConfig struct {
 	Button      CTAButton `yaml:"button,omitempty"`
 }
 
+// BlogSectionConfig represents blog section settings on the landing page
+type BlogSectionConfig struct {
+	Enabled     bool      `yaml:"enabled,omitempty"`
+	Headline    string    `yaml:"headline,omitempty"`
+	Subheadline string    `yaml:"subheadline,omitempty"`
+	MaxPosts    int       `yaml:"max_posts,omitempty"`    // default 3
+	ShowExcerpt bool      `yaml:"show_excerpt,omitempty"` // show subtitle as excerpt
+	CTAButton   CTAButton `yaml:"cta_button,omitempty"`   // "View All Posts" link
+}
+
 // FooterConfig represents footer settings
 type FooterConfig struct {
 	Links         []FooterLink `yaml:"links,omitempty"`