Refactored Redis resource include macro and increased memory limits

- Replaced deprecated lookup(vars=...) in svc-db-redis with macro-based include (Ansible/Jinja safe)
- Redis now uses higher resource values (1 CPU, 1G reserved, 8G max, 512 pids)
- Enables stable Whiteboard operation with >3.5 GB Redis memory usage
- Related conversation: https://chatgpt.com/share/68f67a00-d598-800f-a6be-ee5987e66fba

roles/web-app-nextcloud/config/main.yml

@@ -33,10 +33,10 @@ docker:
   services:
     redis:
       enabled:              true
-      cpus:                 "0.25"
-      mem_reservation:      "64m"
-      mem_limit:            "256m"
-      pids_limit:           256
+      cpus:                 "1"
+      mem_reservation:      "1g"
+      mem_limit:            "8g"
+      pids_limit:           512
     database:
       enabled:              true
       cpus:                 "0.75"