feat(terraform): import Longhorn StorageClasses and app PVCs to Terraform state

- Phase 1: longhorn, longhorn-kafka StorageClasses (cluster-wide defaults)
- Phase 2 pilot: grafana, loki, portainer, forgejo PVCs
- All imports protected by lifecycle.prevent_destroy
- Removes Helm annotations (meta.helm.sh/*) to prevent dual-ownership conflicts
- Remote state backend (MinIO S3) syncs automatically on plan/apply
- Import-only approach: zero data loss, existing volumes untouched
- See terraform/LONGHORN_PVC_IMPORT.md for execution record

Co-Authored-By: Claude Haiku 4.5 <[email protected]>

terraform/state.tf

@@ -5,6 +5,7 @@ terraform {
     key                         = "homelab/terraform.tfstate"
     region                      = "us-east-1"
     endpoint                    = "https://minio-api.riotpiao.homelab.com"
+    profile                     = "minio"
     skip_credentials_validation = true
     skip_requesting_account_id  = true
     skip_region_validation      = true