feat: implement reading progress tracking system

Database & API:
- Enhanced ReadingHistory model with versionId field and unique constraint per user/version
- Created /api/user/reading-progress endpoint (GET/POST) for saving and retrieving progress
- Upsert operation ensures one reading position per user per Bible version

Bible Reader Features:
- Auto-save reading position after 2 seconds of inactivity
- Auto-restore last reading position on page load (respects URL parameters)
- Visual progress bar showing completion percentage based on chapters read
- Calculate progress across entire Bible (current chapter / total chapters)
- Client-side only loading to prevent hydration mismatches

Bug Fixes:
- Remove 200 version limit when loading "all versions" - now loads ALL versions
- Fix version selection resetting to favorite when user manually selects different version
- Transform books API response to include chaptersCount property
- Update service worker cache version to force client updates
- Add comprehensive SEO URL logging for debugging 404 issues

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

prisma/schema.prisma

@@ -277,6 +277,7 @@ model UserPrayer {
 model ReadingHistory {
   id          String   @id @default(uuid())
   userId      String
+  versionId   String   // Bible version ID
   bookId      String
   chapterNum  Int
   verseNum    Int?
@@ -285,6 +286,8 @@ model ReadingHistory {
   user        User     @relation(fields: [userId], references: [id], onDelete: Cascade)
 
   @@index([userId, viewedAt])
+  @@index([userId, versionId])
+  @@unique([userId, versionId]) // Only one reading position per user per version
 }
 
 model UserPreference {