feat: add SEO fields to settings configuration

content/settings.yaml.example

@@ -6,6 +6,14 @@
 title: "My Portfolio"
 subtitle: "A visual journal"
 
+# ── SEO & Metadata ───────────────────────────────────────────────
+# Optional: Overrides global title/subtitle for search engines and social cards
+# seo:
+#   title: "My Portfolio | Photography"
+#   description: "A curated selection of my best photography work."
+#   noIndex: false # Set to true to hide from search engines
+#   noFollow: false # Set to true to prevent search engines from following links
+
 # Show EXIF metadata (camera, lens, ISO) on photo grid hover
 exifOnHover: true