Add structured show notes form to Episode Highlights; v1.2.3

Replace single showNotes textarea with five guided fields: Episode Summary,
Key Themes, Scripture References, Key Quotes, and Resources & Links. Legacy
showNotes content is preserved as a backward-compatible fallback — it
auto-populates the Summary field in the admin editor and renders on the public
episode detail page until overwritten with structured data.

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "1.2.2",
+  "version": "1.2.3",
   "type": "module",
   "scripts": {
     "dev": "vite",