fix(directus): resolve critical deployment issues

- Remove duplicate directus-extensions volume mount (conflict)
- Fix FORCE_FRESH_INSTALL boolean check (handle 'True' from Coolify)
- Optimize healthcheck (10 retries, 60s start period)
- Remove unused named volume definition

All syntax validated:
✅ docker-compose.yaml valid
✅ start.sh syntax OK
✅ Extensions structure correct
✅ SQL schema present

start.sh

@@ -27,7 +27,7 @@ if [ $DB_READY = false ]; then
 fi
 
 # === Fresh Install Mode ===
-if [ "$FORCE_FRESH_INSTALL" = "true" ]; then
+if [ "$FORCE_FRESH_INSTALL" = "true" ] || [ "$FORCE_FRESH_INSTALL" = "True" ]; then
     echo ""
     echo "⚠️  ============================================"
     echo "⚠️  FORCE_FRESH_INSTALL MODE ACTIVATED"