Revamp /admin with drill-down sidebar nav and focused sub-views; v1.1.50

- Replace flat sidebar with accordion nav: parent items (Homepage, About,
  Contact, Podcast Hub) expand to reveal focused sub-items
- Split big sections into granular sub-views so each form shows only 3-8
  fields (Homepage: Hero/Share/PRISM/Where-to-Next, About: Show Copy/Bio/
  Testimonials, Contact: Profile/Copy & Scripture, Podcast: Current Series/
  Highlights/Finished Books/Scripts/RSS)
- New topbar: brand + breadcrumb (Homepage › Hero), clean gold Save Draft
  button, ghost Preview/Publish buttons — no more jump-to select
- New sidebar: compact 196px width, filter input at top, small-caps group
  labels, chevron-animated parent items, indented sub-items with active
  highlight, Back-to-site/Log-out/version at the bottom
- Replace PodcastTab state with adminView sub-views (podcast:current-series
  etc.) eliminating the secondary tab bar inside the panel
- Extend AdminView type with all new colon-separated sub-view values

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

package.json

@@ -1,7 +1,7 @@
 {
   "name": "siteforge",
   "private": true,
-  "version": "1.1.49",
+  "version": "1.1.50",
   "type": "module",
   "scripts": {
     "dev": "vite",