feat(frontend): add Helm chart browser, monitoring, chart-references and values templates pages

Add new frontend pages for the multi-tenant OCDP platform:

- Charts page (/charts): Browse Harbor OCI registries to list Helm chart repositories
  and versions, with deploy modal to launch charts on selected clusters
- Monitoring page (/monitoring): Display cluster metrics (CPU/Memory/GPU usage)
  and per-node details with resource utilization bars
- Chart References page (/chart-references): CRUD for chart metadata references
- Values Templates page (/templates): CRUD for Helm values templates with version
  history and rollback support
- Sidebar: Add Charts navigation, update Storage and Templates links
- api.ts: Add all API client functions (clusterApi, registryApi, instanceApi,
  monitoringApi, storageApi, chartReferenceApi, valuesTemplateApi,
  workspaceApi, userApi) with full TypeScript types

Note: deploy flow and values template rollback not yet end-to-end tested.

backend/internal/adapter/output/persistence/postgres/quota_repository.go

@@ -0,0 +1,212 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/ocdp/cluster-service/internal/domain/entity"
+	"github.com/ocdp/cluster-service/internal/domain/repository"
+)
+
+// QuotaRepository PostgreSQL 配额仓储实现
+type QuotaRepository struct {
+	db *DB
+}
+
+// NewQuotaRepository 创建 PostgreSQL 配额仓储
+func NewQuotaRepository(db *DB) repository.QuotaRepository {
+	return &QuotaRepository{db: db}
+}
+
+// Create 创建配额
+func (r *QuotaRepository) Create(ctx context.Context, quota *entity.WorkspaceQuota) error {
+	if quota.ID == "" {
+		quota.ID = uuid.New().String()
+	}
+
+	query := `
+		INSERT INTO workspace_quotas (id, workspace_id, resource_type, hard_limit, soft_limit, used, created_at, updated_at)
+		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+		ON CONFLICT (workspace_id, resource_type) DO UPDATE
+		SET hard_limit = $4, soft_limit = $5, updated_at = $8
+	`
+
+	_, err := r.db.conn.ExecContext(ctx, query,
+		quota.ID,
+		quota.WorkspaceID,
+		quota.ResourceType,
+		quota.HardLimit,
+		quota.SoftLimit,
+		quota.Used,
+		quota.CreatedAt,
+		quota.UpdatedAt,
+	)
+
+	if err != nil {
+		return fmt.Errorf("failed to create quota: %w", err)
+	}
+
+	return nil
+}
+
+// GetByID 根据 ID 获取配额
+func (r *QuotaRepository) GetByID(ctx context.Context, id string) (*entity.WorkspaceQuota, error) {
+	query := `
+		SELECT id, workspace_id, resource_type, hard_limit, soft_limit, used, created_at, updated_at
+		FROM workspace_quotas
+		WHERE id = $1
+	`
+
+	quota := &entity.WorkspaceQuota{}
+	err := r.db.conn.QueryRowContext(ctx, query, id).Scan(
+		&quota.ID,
+		&quota.WorkspaceID,
+		&quota.ResourceType,
+		&quota.HardLimit,
+		&quota.SoftLimit,
+		&quota.Used,
+		&quota.CreatedAt,
+		&quota.UpdatedAt,
+	)
+
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("failed to get quota: %w", err)
+	}
+
+	return quota, nil
+}
+
+// GetByWorkspaceAndType 根据 workspace 和资源类型获取配额
+func (r *QuotaRepository) GetByWorkspaceAndType(ctx context.Context, workspaceID string, resourceType entity.ResourceType) (*entity.WorkspaceQuota, error) {
+	query := `
+		SELECT id, workspace_id, resource_type, hard_limit, soft_limit, used, created_at, updated_at
+		FROM workspace_quotas
+		WHERE workspace_id = $1 AND resource_type = $2
+	`
+
+	quota := &entity.WorkspaceQuota{}
+	err := r.db.conn.QueryRowContext(ctx, query, workspaceID, resourceType).Scan(
+		&quota.ID,
+		&quota.WorkspaceID,
+		&quota.ResourceType,
+		&quota.HardLimit,
+		&quota.SoftLimit,
+		&quota.Used,
+		&quota.CreatedAt,
+		&quota.UpdatedAt,
+	)
+
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("failed to get quota: %w", err)
+	}
+
+	return quota, nil
+}
+
+// GetByWorkspace 获取 workspace 的所有配额
+func (r *QuotaRepository) GetByWorkspace(ctx context.Context, workspaceID string) ([]*entity.WorkspaceQuota, error) {
+	query := `
+		SELECT id, workspace_id, resource_type, hard_limit, soft_limit, used, created_at, updated_at
+		FROM workspace_quotas
+		WHERE workspace_id = $1
+		ORDER BY resource_type
+	`
+
+	rows, err := r.db.conn.QueryContext(ctx, query, workspaceID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list quotas: %w", err)
+	}
+	defer rows.Close()
+
+	quotas := make([]*entity.WorkspaceQuota, 0)
+	for rows.Next() {
+		quota := &entity.WorkspaceQuota{}
+		err := rows.Scan(
+			&quota.ID,
+			&quota.WorkspaceID,
+			&quota.ResourceType,
+			&quota.HardLimit,
+			&quota.SoftLimit,
+			&quota.Used,
+			&quota.CreatedAt,
+			&quota.UpdatedAt,
+		)
+		if err != nil {
+			return nil, fmt.Errorf("failed to scan quota: %w", err)
+		}
+		quotas = append(quotas, quota)
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("rows iteration error: %w", err)
+	}
+
+	return quotas, nil
+}
+
+// Update 更新配额
+func (r *QuotaRepository) Update(ctx context.Context, quota *entity.WorkspaceQuota) error {
+	quota.UpdatedAt = time.Now()
+
+	query := `
+		UPDATE workspace_quotas
+		SET hard_limit = $1, soft_limit = $2, used = $3, updated_at = $4
+		WHERE id = $5
+	`
+
+	result, err := r.db.conn.ExecContext(ctx, query,
+		quota.HardLimit,
+		quota.SoftLimit,
+		quota.Used,
+		quota.UpdatedAt,
+		quota.ID,
+	)
+
+	if err != nil {
+		return fmt.Errorf("failed to update quota: %w", err)
+	}
+
+	rows, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("failed to get affected rows: %w", err)
+	}
+
+	if rows == 0 {
+		return fmt.Errorf("quota not found")
+	}
+
+	return nil
+}
+
+// Delete 删除配额
+func (r *QuotaRepository) Delete(ctx context.Context, id string) error {
+	query := `DELETE FROM workspace_quotas WHERE id = $1`
+
+	_, err := r.db.conn.ExecContext(ctx, query, id)
+	if err != nil {
+		return fmt.Errorf("failed to delete quota: %w", err)
+	}
+
+	return nil
+}
+
+// DeleteByWorkspace 删除 workspace 的所有配额
+func (r *QuotaRepository) DeleteByWorkspace(ctx context.Context, workspaceID string) error {
+	query := `DELETE FROM workspace_quotas WHERE workspace_id = $1`
+
+	_, err := r.db.conn.ExecContext(ctx, query, workspaceID)
+	if err != nil {
+		return fmt.Errorf("failed to delete quotas: %w", err)
+	}
+
+	return nil
+}