feat: add 5 notification mutations + comprehensive refactors from PR review

New notification actions (archive_many, create_unique, unarchive_many,
unarchive_all, recalculate) bring unraid_notifications to 14 actions.

Also includes continuation of CodeRabbit/PR review fixes:
- Remove redundant try-except in virtualization.py (silent failure fix)
- Add QueryCache protocol with get/put/invalidate_all to core/client.py
- Refactor subscriptions (manager, diagnostics, resources, utils)
- Update config (logging, settings) for improved structure
- Expand test coverage: http_layer, safety guards, schema validation
- Minor cleanups: array, docker, health, keys tools

Co-authored-by: Claude <noreply@anthropic.com>

docker-compose.yml

@@ -11,6 +11,7 @@ services:
     tmpfs:
       - /tmp:noexec,nosuid,size=64m
       - /app/logs:noexec,nosuid,size=16m
+      - /app/.cache/logs:noexec,nosuid,size=8m
     ports:
       # HostPort:ContainerPort (maps to UNRAID_MCP_PORT inside the container, default 6970)
       # Change the host port (left side) if 6970 is already in use on your host