perf: Comprehensive efficiency optimizations

Implemented all 5 critical efficiency improvements to optimize
performance, reduce resource usage, and improve scalability.

## 1. Database Indexes
- Added indexes on sermon_notes foreign keys (user_id, sermon_id)
- Added composite index on sermons (archived, date DESC)
- Added indexes on frequently queried columns across all tables
- Impact: Faster queries as data grows, better JOIN performance

## 2. Eliminated N+1 Query Pattern
- Reduced 2 API calls to 1 on home page load
- Changed from separate active/archived fetches to single call
- Filter archived sermons client-side using computed properties
- Impact: 50% reduction in HTTP requests per page load

## 3. Scheduled Database Cleanup
- Extended existing plugin to clean expired sessions hourly
- Added cleanup for expired rate limits every hour
- Added cleanup for expired password reset codes every hour
- Sermon cleanup continues to run daily based on retention policy
- Impact: Prevents database table growth, better performance

## 4. Multi-stage Docker Build
- Implemented 3-stage build: deps -> builder -> runtime
- Separated build-time and runtime dependencies
- Added non-root user (nuxt:nodejs) for security
- Integrated dumb-init for proper signal handling
- Added health check endpoint at /api/health
- Impact: Smaller image size, faster deployments, better security

## 5. HTTP Caching
- Static assets: 1 year cache (immutable)
- Logos/images: 1 year cache (immutable)
- API routes: No cache (always fresh)
- HTML pages: 10 minute cache with revalidation
- Impact: Reduced bandwidth, faster page loads, less server load

All optimizations follow best practices and maintain backward
compatibility with existing functionality.

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

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

pages/index.vue

@@ -200,17 +200,20 @@ const greeting = computed(() => {
   return `${timeGreeting}, ${firstName.value}!`
 })
 
-// Fetch non-archived sermons for the most recent sermon
-const { data: activeSermons } = await useFetch('/api/sermons?includeArchived=false')
-
-// Fetch archived sermons for the previous sermons dropdown
-const { data: archivedSermons } = await useFetch('/api/sermons?includeArchived=true')
+// Fetch all sermons in a single request (more efficient than two separate calls)
+const { data: allSermons } = await useFetch('/api/sermons?includeArchived=true')
 
 const selectedSermonSlug = ref('')
 
+// Filter active (non-archived) sermons client-side
+const activeSermons = computed(() => {
+  if (!allSermons.value) return []
+  return allSermons.value.filter((s: any) => s.archived !== 1)
+})
+
 // Get today's sermon (if one exists for today's date)
 const todaysSermon = computed(() => {
-  if (!activeSermons.value || activeSermons.value.length === 0) return null
+  if (activeSermons.value.length === 0) return null
   
   const today = new Date()
   today.setHours(0, 0, 0, 0)
@@ -222,7 +225,7 @@ const todaysSermon = computed(() => {
     if (sermonDate.getTime() === today.getTime()) {
       return { ...s, displayDate: s.date }
     }
-    
+
     // Check additional dates if they exist
     if (s.dates) {
       try {
@@ -232,7 +235,7 @@ const todaysSermon = computed(() => {
           additionalDate.setHours(0, 0, 0, 0)
           return additionalDate.getTime() === today.getTime()
         })
-        
+
         if (matchingDate) {
           return { ...s, displayDate: matchingDate }
         }
@@ -241,13 +244,13 @@ const todaysSermon = computed(() => {
       }
     }
   }
-  
+
   return null
 })
 
 // Get upcoming sermons (future dates)
 const upcomingSermons = computed(() => {
-  if (!activeSermons.value) return []
+  if (activeSermons.value.length === 0) return []
   
   const today = new Date()
   today.setHours(0, 0, 0, 0)
@@ -289,8 +292,8 @@ const upcomingSermons = computed(() => {
 
 // Get archived sermons only for the previous sermons dropdown
 const previousSermons = computed(() => {
-  if (!archivedSermons.value) return []
-  return archivedSermons.value.filter((s: any) => s.archived === 1)
+  if (!allSermons.value) return []
+  return allSermons.value.filter((s: any) => s.archived === 1)
 })
 
 // Check if there are any current or upcoming sermons