[Feature] Phase 6: cluster wiring, Helm chart, operator logic, CLI, and E2E tests

Complete the NovaStor implementation with full cluster wiring:

- gRPC metadata service with JSON-envelope pattern (single Execute RPC)
- gRPC client wrappers for metadata and chunk services
- All 7 binaries wired with real dependencies (no stubs)
- Helm chart with 17 templates for full Kubernetes deployment
- Operator reconcilers with real logic (StoragePool, BlockVolume,
  SharedFilesystem, ObjectStore)
- novactl CLI with cobra (pool/volume/bucket/status commands)
- NFS server upgraded to JSON-RPC protocol
- CSI node with real stage/unstage, NVMe-oF initiator, volume stats
- CSI controller with RWX support
- S3 presigned URLs and object versioning
- Adapter layers bridging S3 and filer interfaces to gRPC clients
- Scrubber rate limiting, cert rotation
- Zap structured logging package
- 6 E2E integration tests (behind //go:build e2e tag)

237 tests passing across 25 packages.

Author: piwi3910

api/proto/metadata/metadata.pb.go

@@ -0,0 +1,39 @@
+syntax = "proto3";
+
+package metadata;
+
+option go_package = "github.com/piwi3910/novastor/api/proto/metadata";
+
+// MetadataService provides gRPC access to the NovaStor metadata store.
+// It uses a generic request/response envelope that carries JSON-encoded
+// domain objects as opaque payloads. This avoids duplicating the rich Go
+// type definitions in protobuf and keeps the wire protocol simple.
+service MetadataService {
+  // Execute performs a single metadata operation identified by the
+  // operation field in MetadataRequest. The payload carries
+  // JSON-encoded arguments; the response payload carries the
+  // JSON-encoded result.
+  rpc Execute(MetadataRequest) returns (MetadataResponse);
+}
+
+// MetadataRequest is the envelope sent by clients for every metadata
+// operation.
+message MetadataRequest {
+  // operation is the method name, e.g. "PutVolumeMeta",
+  // "GetObjectMeta", "ListDirectory", etc.
+  string operation = 1;
+
+  // payload is the JSON-encoded argument(s) for the operation.
+  bytes payload = 2;
+}
+
+// MetadataResponse is the envelope returned by the server.
+message MetadataResponse {
+  // payload is the JSON-encoded result of the operation (may be empty
+  // for void operations that only return an error).
+  bytes payload = 1;
+
+  // error is non-empty when the operation failed. Clients should check
+  // this field before attempting to unmarshal payload.
+  string error = 2;
+}

api/proto/metadata/metadata.proto

@@ -59,11 +59,12 @@ type ErasureCodingSpec struct {
 }
 
 type StoragePoolStatus struct {
-	Phase         string             `json:"phase,omitempty"`
-	NodeCount     int                `json:"nodeCount,omitempty"`
-	TotalCapacity string             `json:"totalCapacity,omitempty"`
-	UsedCapacity  string             `json:"usedCapacity,omitempty"`
-	Conditions    []metav1.Condition `json:"conditions,omitempty"`
+	Phase          string             `json:"phase,omitempty"`
+	NodeCount      int                `json:"nodeCount,omitempty"`
+	TotalCapacity  string             `json:"totalCapacity,omitempty"`
+	UsedCapacity   string             `json:"usedCapacity,omitempty"`
+	DataProtection string             `json:"dataProtection,omitempty"`
+	Conditions     []metav1.Condition `json:"conditions,omitempty"`
 }
 
 // +kubebuilder:object:root=true
@@ -97,6 +98,8 @@ type BlockVolumeSpec struct {
 
 type BlockVolumeStatus struct {
 	Phase      string             `json:"phase,omitempty"`
+	Pool       string             `json:"pool,omitempty"`
+	AccessMode string             `json:"accessMode,omitempty"`
 	NodeID     string             `json:"nodeID,omitempty"`
 	ChunkCount int                `json:"chunkCount,omitempty"`
 	Conditions []metav1.Condition `json:"conditions,omitempty"`