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

src/app/docs/integrations/page.tsx

@@ -27,7 +27,7 @@ export default function DocsIntegrationsPage() {
           Docker (and Docker Compose) is the runtime foundation for every deployment workflow, container lifecycle action,
           service discovery sweep, and template-based launch. DashCaddy communicates with the Docker daemon over the
           Unix socket (<code>/var/run/docker.sock</code>) to start, stop, restart, inspect, and adopt containers, and to
-          deploy the <strong>76+ one-click application templates</strong> from the catalog.
+          deploy the <strong>92+ one-click application templates</strong> from the catalog.
         </p>
         <p>
           The daemon connection is established at startup. If the socket is missing or permissioned for a different user,