Fix: replace non-existent apps with real templates, fix 500 errors on old doc paths

- AppShowcase: Removed 7 non-existent apps (Kaleidescape, Synology Photos, Homelabs, DockSTARTer, Unraid, TrueNAS, New Relic), added 50+ real app templates that exist in code
- Updated template count from 76+ to 92+ across all pages
- Fixed test count from 1400+ to 775+ (actual count)
- Added mod_rewrite fallback for old doc path redirects (fixes 500 errors)
- Added caching, compression, and proper error handling in .htaccess

public/.htaccess

@@ -0,0 +1,34 @@
+# Redirect old doc paths to new ones — using RewriteRule for broader compatibility
+<IfModule mod_rewrite.c>
+  RewriteEngine On
+  RewriteRule ^docs/product-overview/?$ /docs/overview/ [R=301,L]
+  RewriteRule ^docs/deploy-first-service/?$ /docs/first-service/ [R=301,L]
+  RewriteRule ^docs/premium-features/?$ /docs/premium/ [R=301,L]
+  RewriteRule ^docs/infrastructure/?$ /docs/integrations/ [R=301,L]
+</IfModule>
+
+# Fallback using mod_alias Redirect if available
+<IfModule mod_alias.c>
+  Redirect 301 /docs/product-overview /docs/overview/
+  Redirect 301 /docs/deploy-first-service /docs/first-service/
+  Redirect 301 /docs/premium-features /docs/premium/
+  Redirect 301 /docs/infrastructure /docs/integrations/
+</IfModule>
+
+# Set cache headers for static assets
+<IfModule mod_expires.c>
+  ExpiresActive On
+  ExpiresByType text/css "access plus 1 month"
+  ExpiresByType application/javascript "access plus 1 month"
+  ExpiresByType image/png "access plus 1 month"
+  ExpiresByType image/svg+xml "access plus 1 month"
+  ExpiresByType image/x-icon "access plus 1 year"
+</IfModule>
+
+# Enable compression
+<IfModule mod_deflate.c>
+  AddOutputFilterByType DEFLATE text/html text/plain text/css application/javascript application/json
+</IfModule>
+
+# Custom 404 page
+ErrorDocument 404 /404.html